ci(l1): fix unnecesary approval and other minor fixes.

[mpaulucci]

Motivation
Don't get those annoying "approve workflow" messages

Description

• Adds pull_request_target so that the workflow runs in the base repo
• Adds labeled/unlabeled that should fix the problems with the approve workflow

[Copilot]

Pull Request Overview

This PR enhances GitHub workflow configuration to eliminate unnecessary approval prompts for forked PRs and improve workflow responsiveness to label changes.

Key Changes:

• Switches pr_github_metadata.yaml from pull_request to pull_request_target trigger to run workflows in the base repository context
• Adds labeled and unlabeled event types to pr_github_status_l1.yaml to respond to label changes
• Introduces concurrency control to prevent multiple simultaneous workflow runs for the same PR

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
.github/workflows/pr_github_status_l1.yaml	Adds label event triggers, concurrency control, and improves comment clarity
.github/workflows/pr_github_metadata.yaml	Changes trigger to pull_request_target and removes fork check from label job

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[Copilot]

Removing the fork check (if: github.event.pull_request.head.repo.fork == false) while using pull_request_target is dangerous. This allows forked PRs to execute workflows with access to repository secrets and write permissions, creating a potential security vulnerability where malicious code from forks could access sensitive resources.

Suggested change

	name: Set Labels
	name: Set Labels
	if: github.event.pull_request.head.repo.fork == false

[ElFantasma]

Does Copilot have a point here?

[MegaRedHand]

Can you add a comment explaining why we use this instead of pull_request?