[ci] add Python syntax checking workflow on changes to devtools (#5841)

## Summary

Added CI workflow and npm script for Python syntax validation in
devtools directory.

## Changes

- **What**: Added GitHub Actions workflow for Python syntax checking
with `python3 -m compileall`
- **Dependencies**: Added `python3` binary to knip ignore list

## Review Focus

Workflow triggers correctly on devtools path changes and Python syntax
validation covers all relevant files.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-5841-ci-add-Python-syntax-checking-workflow-on-changes-to-devtools-27c6d73d365081b8963dd4600a233852)
by [Unito](https://www.unito.io)

package.json

@@ -38,7 +38,8 @@
     "collect-i18n": "pnpm exec playwright test --config=playwright.i18n.config.ts",
     "json-schema": "tsx scripts/generate-json-schema.ts",
     "storybook": "nx storybook -p 6006",
-    "build-storybook": "storybook build"
+    "build-storybook": "storybook build",
+    "devtools:pycheck": "python3 -m compileall -q tools/devtools"
   },
   "devDependencies": {
     "@eslint/js": "^9.35.0",