CI: remove old patch checks (#104184)

* remove old patch checks

* remove from CODEOWNERS

* rerun CI

.github/workflows/pr-patch-check.yml

@@ -1,27 +0,0 @@
-# Owned by grafana-release-guild
-# Intended to be dropped into the base repo Ex: grafana/grafana
-name: Check for patch conflicts
-run-name: check-patch-conflicts-${{ github.base_ref }}-${{ github.head_ref }}
-on:
-  pull_request:
-    types:
-      - opened
-      - reopened
-      - synchronize
-    branches:
-      - "main"
-      - "v*.*.*"
-      - "release-*"
-
-# Since this is run on a pull request, we want to apply the patches intended for the
-# target branch onto the source branch, to verify compatibility before merging.
-jobs:
-  trigger_downstream_patch_check:
-    uses: grafana/security-patch-actions/.github/workflows/test-patches.yml@main
-    if: github.repository == 'grafana/grafana'
-    with:
-      src_repo: "${{ github.repository }}"
-      src_ref: "${{ github.head_ref }}" # this is the source branch name, Ex: "feature/newthing"
-      patch_repo: "${{ github.repository }}-security-patches"
-      patch_ref: "${{ github.base_ref }}" # this is the target branch name, Ex: "main"
-    secrets: inherit