Add pre-commit, update flake8, run black

.pre-commit-config.yaml

@@ -0,0 +1,8 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+repos:
+  - repo: https://github.com/psf/black-pre-commit-mirror
+    rev: 24.3.0
+    hooks:
+      - id: black
+        files: 'gdb/.*'