🐛 fix: catch ImportError for missing sqlite3 C library (#475)

The previous fix caught ModuleNotFoundError, which only covers the case
where the Python sqlite3 module is entirely absent. In minimal Docker
images the Python package exists but the underlying libsqlite3.so.0 is
missing, raising ImportError instead. Since ModuleNotFoundError is a
subclass of ImportError, catching the parent handles both scenarios.

Author: gaborbernat

src/filelock/__init__.py

@@ -17,7 +17,7 @@
 
 try:
     from ._read_write import ReadWriteLock
-except ModuleNotFoundError:  # sqlite3 may be unavailable if Python was built without it
+except ImportError:  # sqlite3 may be unavailable if Python was built without it or the C library is missing
     ReadWriteLock = None  # type: ignore[assignment, misc]
 
 from ._soft import SoftFileLock

tests/conftest.py

@@ -2,7 +2,7 @@
 
 try:
     from filelock._read_write import _cleanup_connections
-except ModuleNotFoundError:
+except ImportError:
     _cleanup_connections = None  # type: ignore[assignment, misc]