Python: Fix dbscheme/AST autogeneration

There was an errant `ql` in the relevant paths, a leftover from the move
from the internal repo. Also, we can no longer rely on an intree version
of the CodeQL CLI, so from now on we'll just assume it's present in the
path. (On Codespaces, `gh codeql` is a decent replacement, especially if
using the `install-stub` functionality.

Author: tausbn

python/extractor/Makefile

@@ -21,19 +21,19 @@ $(TOKENIZER_FILE): $(TOKENIZER_DEPS)
 
 MASTER_FILE = semmle/python/master.py
 
-DBSCHEME_FILE = $(GIT_ROOT)/ql/python/ql/lib/semmlecode.python.dbscheme
+DBSCHEME_FILE = $(GIT_ROOT)/python/ql/lib/semmlecode.python.dbscheme
 
 .PHONY: dbscheme
 dbscheme: $(MASTER_FILE)
 	python3 -m semmle.dbscheme_gen $(DBSCHEME_FILE)
 
-AST_GENERATED_DIR = $(GIT_ROOT)/ql/python/ql/lib/semmle/python/
+AST_GENERATED_DIR = $(GIT_ROOT)/python/ql/lib/semmle/python/
 AST_GENERATED_FILE = $(AST_GENERATED_DIR)AstGenerated.qll
 
 .PHONY: ast
 ast: $(MASTER_FILE)
 	python3 -m semmle.query_gen $(AST_GENERATED_DIR)
-	$(GIT_ROOT)/target/intree/codeql/codeql query format --in-place $(AST_GENERATED_FILE)
+	codeql query format --in-place $(AST_GENERATED_FILE)
 
 ################################################################################
 # Tests