ci: remove unused workflow_call trigger (Gitea Actions bug go-gitea/gitea#33238)

push + workflow_call in the same on: block doesn't reliably fire push
events on Gitea Actions 1.27 (reproducible upstream, closed as "not
planned" - https://github.com/go-gitea/gitea/issues/33238). Nothing in
this repo invokes build-and-test.yaml via workflow_call anymore after the
workflow cleanup, so removing the trigger is a safe, targeted fix rather
than a workaround.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.github/workflows/README-ci.md

@@ -1 +0,0 @@
-# CI trigger test 2026-07-30T17:32:34Z

.github/workflows/build-and-test.yaml

@@ -17,20 +17,12 @@ on:
         types: [checks_requested]
     push:
         branches: [main]
-
+    # workflow_call entfernt: nichts in diesem Repo ruft build-and-test.yaml per
-    # support triggering from other workflows
+    # workflow_call auf (verifiziert), und die Kombination push+workflow_call im
-    workflow_call:
+    # selben on:-Block triggert auf Gitea Actions 1.27 nicht zuverlaessig bei push
-        inputs:
+    # (bekannter, als "not planned" geschlossener Gitea-Bug #33238). inputs.skip/
-            skip:
+    # inputs.matrix-js-sdk-sha bleiben unten referenziert, werten fuer alle
-                type: boolean
+    # verbleibenden Trigger-Typen einfach zu null/leer aus (unveraendertes Verhalten).
-                required: false
-                default: false
-                description: "A boolean to skip the playwright check itself while still creating the passing check. Useful when only running in Merge Queues."
-
-            matrix-js-sdk-sha:
-                type: string
-                required: false
-                description: "The Git SHA of matrix-js-sdk to build against. By default, will use a matching branch name if it exists, or develop."
 
 concurrency:
     group: ${{ github.workflow }}-${{ github.ref }}-${{ github.event_name }}