Add GDPR classification for environments extension telemetry - #26097

PR classified as team-member.

⚠️ Head commit is NOT signed by a trusted team member, so the full 2-approval requirement applies. (Head commit signature not verified (reason: unsigned).)

Tip: to earn the credit (−1 approval), the head commit must be signed by you with one of your own keys listed in security/trusted-signing-keys.csv. A "Verified" badge that GitHub adds to commits it creates on your behalf — web-editor edits, applied suggestions, Codespaces, API commits — does not count.

✅ Collaborator approvals: 2/2 (StellaHuang95, rchiodo).

✅ No newly added runnable binary files.

✅ No protected engineering system files changed.