Add scheduled workflow to auto-remove old CI artifacts (#815)

* Initial plan

* Add workflow to remove old artifacts

Agent-Logs-Url: https://github.com/irihitech/Semi.Avalonia/sessions/ac7e9f88-0a15-4dfe-aae7-64cda4c5ad1e

Co-authored-by: rabbitism <14807942+rabbitism@users.noreply.github.com>

* ci: add workflow_dispatch trigger to remove-old-artifacts.yml.

* ci: add remove-old-artifacts.yml to solution file.

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: rabbitism <14807942+rabbitism@users.noreply.github.com>
Co-authored-by: Zhang Dian <54255897+zdpcdt@users.noreply.github.com>

.github/workflows/remove-old-artifacts.yml

@@ -0,0 +1,25 @@
+name: Remove old artifacts
+
+on:
+  schedule:
+    # Every day at 1am
+    - cron: '0 1 * * *'
+  workflow_dispatch:
+
+jobs:
+  remove-old-artifacts:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    # For private repos
+    permissions:
+      actions: write
+
+    steps:
+    - name: Remove old artifacts
+      uses: c-hive/gha-remove-artifacts@v1
+      with:
+        age: '15 days' # '<number> <unit>', e.g. 5 days, 2 years, 90 seconds, parsed by Moment.js
+        # Optional inputs
+        skip-tags: true
+        skip-recent: 5