refactor: remove CodeQL custom queries directory for Python

- Delete codeql-custom-queries-python directory and all contents
- Remove codeql-pack.yml configuration file
- Remove codeql-pack.lock.yml dependency lock file
- Remove example.ql hello world query

dev/codeql-custom-queries-python/example.ql

@@ -0,0 +1,12 @@
+/**
+ * This is an automatically generated file
+ * @name Hello world
+ * @kind problem
+ * @problem.severity warning
+ * @id python/example/hello-world
+ */
+
+import python
+
+from File f
+select f, "Hello, world!"