release.py expects Euphonic to be installed already

This seems like overkill, we have already been quite careful to create
consistent version information. But it wouldn't hurt to have these
checks running for an automated release cycle before we consider
pruning them.

.github/workflows/release.yml

@@ -53,7 +53,16 @@ jobs:
           ref: ${{ inputs.ref }}
           fetch-depth: 1
 
-      - name:
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.10"
+
+      - name: Basic installation to check euphonic.__version__
+        shell: bash -l {0}
+        run: |
+          python -m pip install .
+
+      - name: Check version consistency, generate Github release page
         run : |
           python build_utils/release.py --github ${{ inputs.push && '--notest' || '' }}