Revert openblas linking changes from #451 (#1386)

PR #451 introduced linking against both OpenBLAS and LAPACKE+Accelerate
on arm macOS, which breaks re-compilation of certain user programs (like
Shor's). The cause of the shared library conflict is unknown.

For now, we revert these linking changes, which were originally
introduced due to Lightning not finding its OpenBLAS dependency when
invoked through Catalyst:
```
FAILED frontend/test/pytest/test_measurements_shots_results.py::TestExpval::test_hermitian[lightning.qubit]

RuntimeError: [pennylane_lightning/core/src/utils/SharedLibLoader.hpp][Line:60][Method:SharedLibLoader]: Error in PennyLane Lightning: dlopen(libscipy_openblas.dylib, 0x0001): tried: 'libscipy_openblas.dylib' (no such file), '$ORIGIN/../scipy_openblas32/lib/libscipy_openblas.dylib' (no such file)
```

The above test will fail as a result of this, which we plan to fix with
a PR on the lightning side.

[sc-80803]

.dep-versions

@@ -12,4 +12,4 @@ pennylane=0.40.0-dev20
 
 # For a custom LQ/LK version, update the package version here and at
 # 'doc/requirements.txt'
-lightning=0.40.0-dev30
+lightning=0.40.0-dev41

.github/workflows/build-wheel-macos-arm64.yaml

@@ -51,6 +51,7 @@ jobs:
     - name: Checkout Catalyst repo
       uses: actions/checkout@v4
 
+    # Python 3.10 was dropped from the GH images on macOS arm
     - name: Install Python 3.10
       uses: actions/setup-python@v5
       with:
@@ -235,8 +236,10 @@ jobs:
     - name: Checkout Catalyst repo
       uses: actions/checkout@v4
 
+    # Python 3.10 was dropped from the GH images on macOS arm
     - name: Install Python 3.10
       uses: actions/setup-python@v5
+      if: ${{ matrix.python_version }} == '3.10'
       with:
         python-version: '3.10'
 
@@ -418,10 +421,12 @@ jobs:
     - name: Checkout Catalyst repo
       uses: actions/checkout@v4
 
-    - name: Install Python ${{ matrix.python_version }}
+    # Python 3.10 was dropped from the GH images on macOS arm
+    - name: Install Python 3.10
       uses: actions/setup-python@v5
+      if: ${{ matrix.python_version }} == '3.10'
       with:
-        python-version: ${{ matrix.python_version }}
+        python-version: '3.10'
 
     - name: Download Wheel Artifact
       uses: actions/download-artifact@v4
@@ -453,7 +458,6 @@ jobs:
         python${{ matrix.python_version }} -m pip install PennyLane-Lightning-Kokkos
         python${{ matrix.python_version }} -m pip install 'amazon-braket-pennylane-plugin>1.27.1'
 
-
     - name: Install OQC client
       run: |
         python${{ matrix.python_version }} -m pip install oqc-qcaas-client

doc/requirements.txt

@@ -30,6 +30,6 @@ lxml_html_clean
 
 # Pre-install PL development wheels
 --extra-index-url https://test.pypi.org/simple/
-pennylane-lightning-kokkos==0.40.0-dev30
-pennylane-lightning==0.40.0-dev30
+pennylane-lightning-kokkos==0.40.0-dev41
+pennylane-lightning==0.40.0-dev41
 pennylane==0.40.0-dev20

frontend/catalyst/compiler.py

@@ -121,25 +121,24 @@ def get_default_flags(options):
         path_within_package = "lib"
         file_extension = ".so" if platform.system() == "Linux" else ".dylib"  # pragma: no branch
 
-        package_spec = importlib.util.find_spec(package_name)
-        package_directory = path.dirname(package_spec.origin)
-        lapack_lib_path = path.join(package_directory, path_within_package)
-
-        search_pattern = path.join(lapack_lib_path, f"lib*{lib_name}*{file_extension}")
-        search_result = glob.glob(search_pattern)
-        if not search_result:  # pragma: nocover
-            raise CompileError(
-                f'Unable to find OpenBLAS library at "{search_pattern}". '
-                "Please ensure that scipy is installed and available via pip."
-            )
-
-        lib_path_flags += [f"-Wl,-rpath,{lapack_lib_path}", f"-L{lapack_lib_path}"]
-        lapack_lib_name = path.basename(search_result[0])[3 : -len(file_extension)]
-
-        lapack_libs = [lapack_lib_name]
         if platform.system() == "Darwin" and platform.machine() == "arm64":  # pragma: nocover
             # use our own build of LAPACKe to interface with Accelerate
-            lapack_libs += ["lapacke.3"]
+            lapack_lib_name = "lapacke.3"
+        else:
+            package_spec = importlib.util.find_spec(package_name)
+            package_directory = path.dirname(package_spec.origin)
+            lapack_lib_path = path.join(package_directory, path_within_package)
+
+            search_pattern = path.join(lapack_lib_path, f"lib*{lib_name}*{file_extension}")
+            search_result = glob.glob(search_pattern)
+            if not search_result:  # pragma: nocover
+                raise CompileError(
+                    f'Unable to find OpenBLAS library at "{search_pattern}". '
+                    "Please ensure that scipy is installed and available via pip."
+                )
+
+            lib_path_flags += [f"-Wl,-rpath,{lapack_lib_path}", f"-L{lapack_lib_path}"]
+            lapack_lib_name = path.basename(search_result[0])[3 : -len(file_extension)]
 
         system_flags = []
         if platform.system() == "Linux":
@@ -159,8 +158,6 @@ def get_default_flags(options):
         elif options.async_qnodes and platform.system() == "Darwin":  # pragma: nocover
             system_flags += ["-lc++"]
 
-        lapack_libs = [f"-l{name}" for name in lapack_libs]
-
         default_flags = [
             "-shared",
             "-rdynamic",
@@ -169,7 +166,7 @@ def get_default_flags(options):
             "-lrt_capi",
             "-lpthread",
             "-lmlir_c_runner_utils",  # required for memref.copy
-            *lapack_libs,
+            f"-l{lapack_lib_name}",  # required for custom_calls lib
             "-lcustom_calls",
             "-lmlir_async_runtime",
         ]