chore(build): update copyright headers and pre-commit hook #1736

[yesudeep]

Issue: #1736

The copyright headers in Python files have been updated to include SPDX license identifier and change "Google Inc." to "Google LLC". Additionally, simplified the pre-commit hook command for branch protection.

CHANGELOG:

• chore: update copyright header to use "Google LLC" instead of "Google Inc."
• chore: add SPDX-License-Identifier to copyright headers
• build: simplify no-commits-on-branches pre-commit hook command by removing 'py' argument
• feat: add check licenses script for later use
• chore: remove spurious .projectile file that would cause emacs to tighten scope
• refactor: move PATH environment variable handling into its own function
• feat: add govulncheck to check for known vulnerabilities in dependencies
• feat: add cleanup temp files script
• chore: configure ci checks to run regardless of directory modified to catch cross-runtime errors

Checklist (if applicable):

• PR title is following https://www.conventionalcommits.org/en/v1.0.0/
• Tested (manually, unit tested, etc.)
• Docs updated (updated docs or a docs bug required)

[yesudeep]

It looks like the picoschema_tests.yaml file has been removed when the dotprompt directory was removed and since the go tests didn't run when that happened, they're failing.

Hmm... It looks like there is common stuff between runtimes and we should run the tests for all runtimes whenever we make changes.

#1695

[yesudeep]

Temporarily disabled breaking test and assigned to @hugoaguirre to address.
See: #1741