fix: allow os_walk to follow symlinks (#3026)

Allows the testinfra verifier to follow symlinks in the tests
directory.

This fixes a bug described here:
#3021

src/molecule/util.py

@@ -160,9 +160,9 @@ def run_command(
     return result
 
 
-def os_walk(directory, pattern, excludes=[]):
+def os_walk(directory, pattern, excludes=[], followlinks=False):
     """Navigate recursively and retried files based on pattern."""
-    for root, dirs, files in os.walk(directory, topdown=True):
+    for root, dirs, files in os.walk(directory, topdown=True, followlinks=followlinks):
         dirs[:] = [d for d in dirs if d not in excludes]
         for basename in files:
             if fnmatch.fnmatch(basename, pattern):

src/molecule/verifier/testinfra.py

@@ -196,7 +196,12 @@ def _get_tests(self):
         :return: list
         """
         return sorted(
-            [filename for filename in util.os_walk(self.directory, "test_*.py")]
+            [
+                filename
+                for filename in util.os_walk(
+                    self.directory, "test_*.py", followlinks=True
+                )
+            ]
         )
 
     def schema(self):