chore(webgpu/generate): spec builds from clean pull

Author: MendyBerger

webgpu/generate/.gitignore

@@ -1 +1,2 @@
-/target
+/target
+/.venv

webgpu/generate/generate.sh

@@ -1,5 +1,13 @@
+set -euo pipefail
+
+if [ ! -d .venv ]; then
+    python3 -m venv .venv
+fi
+source .venv/bin/activate
+
 cd ./webgpu-spec
-make -j
+bash tools/install-dependencies.sh bikeshed
+make -j spec
 cd ..
 
 cargo run