Fix build and delete superfluous files

- Make Python make formatting pristine
- Add missing `#pragma weak` to Python source
- Fix Clang script flake due to missing directory

test/libc/release/metal.sh

@@ -8,6 +8,8 @@ if [ "$MODE" = opt ]; then
   exit
 fi
 
+mkdir -p o/$MODE/test/libc/release/
+
 # smoke test booting on bare metal and printing data to serial uart
 CMD="o/$MODE/tool/build/blinkenlights.com.dbg -r o/$MODE/examples/hello.com"
 if OUTPUT="$($CMD)"; then