Add build self-host stub (#107)

.github/workflows/build-self-host.yml

@@ -0,0 +1,16 @@
+---
+name: Build Self-Host
+
+on:
+  workflow_dispatch:
+
+jobs:
+  stub:
+    name: Stub
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
+
+      - name: Stub
+        run: echo "Stub"