impr(ci): switch release PR creation over to use python based action (#11679)

## Problem
Our different repositories had both had code to achieve very similar
results in terms of release PR creation, but they were structured
differently and had different extensions. This was likely to cause
maintainability problems in the long run.

## Summary of changes
Switch to a python cli based composite action for creating the release
PRs that will also be introduced in our other repos later.

## To Do
- [ ] Adjust our docs to reflect the changes from this.

.github/workflows/release-proxy.yml

@@ -0,0 +1,12 @@
+name: Create proxy release PR
+
+on:
+  schedule:
+    - cron: '0 6 * * TUE'
+
+jobs:
+  create-release-pr:
+    uses: ./.github/workflows/release.yml
+    with:
+      component: proxy
+    secrets: inherit