Exclude imported tests from CodeQL analysis

The historical gitdb and smmap test suites contain intentional legacy uses
of tempfile.mktemp. Importing them made GitPython's CodeQL workflow report
new security findings even though the code is test-only and unchanged from
the standalone projects.

Ignore only the imported test directories while continuing to analyze all
three production packages.

Author: codex

.github/workflows/codeql.yml

@@ -62,6 +62,10 @@ jobs:
       with:
         languages: ${{ matrix.language }}
         build-mode: ${{ matrix.build-mode }}
+        config: |
+          paths-ignore:
+            - gitdb/gitdb/test/**
+            - smmap/smmap/test/**
         # If you wish to specify custom queries, you can do so here or in a config file.
         # By default, queries listed here will override any specified in a config file.
         # Prefix the list here with "+" to use these queries and those in the config file.