ci: add advance-deploy-env caller to .github (re-land — tickets stuck at FR on dev)

[LukasWodka]

Re-lands the advance-deploy-env caller for .github. It was meant to be in #76 but the commit was orphaned (pushed after #76 merged), so .github's kanban items still don't advance to Prod when code ships to main.

.github hosts the reusable but had no push-triggered caller of its own — the only repo missing one. This adds it. After merge, promote to main so it runs on future .github promotions.

Refs the 'why are shipped tickets stuck at FR on dev' thread.

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Note

Low Risk
CI-only addition that reuses an existing org workflow on branch pushes; no application, auth, or data-path changes.

Overview
Adds advance-deploy-env-caller.yml, which runs on pushes to develop, staging, master, and main and invokes the existing reusable advance-deploy-env.yml with inherited secrets.

The .github repo already hosted that reusable workflow but was the only repo without a push-triggered caller, so kanban items tied to this repo did not advance with deploys (e.g. tickets stuck at FR on dev while promotions alone reached Prod). This aligns .github with the other repos so merges to main can auto-advance contained tickets to Prod.

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[LukasWodka]

👋 Heads-up — Code review queue is at 39 / 30

Above the WIP limit. The team convention is to review existing PRs before opening new work.

Open PRs currently in Code review (oldest first):

• averaging-service#207 — Promote develop → staging · author: @shujaatTracebloc · no reviewer assigned
• backend#1201 — docs(rfc): Data spaces & federated dataset composition (draft) · author: @LukasWodka · no reviewer assigned
• backend#1217 — docs(rfc): Dataset integrity & score reproducibility (draft) · author: @LukasWodka · no reviewer assigned
• backend#1228 — Promote develop → staging · author: @shujaatTracebloc · reviewer: @saadqbal
• backend#1244 — fix(experiments): surface save-time failures as 5xx + guard new NOT NULL columns · author: @LukasWodka · reviewer: @saqlainsyed007
• backend#1251 — docs(bugbot): add .cursor/BUGBOT.md project context (#930) · author: @LukasWodka · no reviewer assigned
• backend#1254 — docs(pr-template): owner-qualify cross-repo closing keywords · author: @LukasWodka · no reviewer assigned
• backend#1259 — docs(rfc): qualified RFC identifiers + org-wide index · author: @LukasWodka · no reviewer assigned
• backend#1261 — RFC-BACKEND-0008: board & process reset (decision RFC — for markup) · author: @LukasWodka · no reviewer assigned
• cli#397 — Release develop → main · author: @shujaatTracebloc · no reviewer assigned

Pull from review before opening new work. (This is a nudge from the kanban WIP check, not a block.)