.github: allow repo checkout override

Needed when called by spins inside different organizations.

.github/workflows/build.yml

@@ -13,6 +13,12 @@ on:
         required: false
         default: true
         type: boolean
+      infix_repo:
+        description: 'Repo to checkout (for spin overrides)'
+        required: false
+        default: kernelkit/infix
+        type: string
+
 
   workflow_call:
     inputs:
@@ -26,9 +32,14 @@ on:
         required: false
         type: boolean
         default: true
+      infix_repo:
+        required: false
+        type: string
+        default: kernelkit/infix
 
 env:
   MINIMAL: ${{ github.event_name == 'workflow_dispatch' && github.event.inputs.minimal || inputs.minimal }}
+  INFIX_REPO: ${{ github.event_name == 'workflow_dispatch' && github.event.inputs.infix_repo || inputs.infix_repo }}
 
 
 jobs:
@@ -47,8 +58,11 @@ jobs:
           rm -rf ./.??* || true
           ls -la ./
 
-      - uses: actions/checkout@v4
+      - name: Checkout infix repo
+        uses: actions/checkout@v4
         with:
+          repository: ${{ env.INFIX_REPO }}
+          ref: ${{ github.ref }}
           clean: true
           fetch-depth: 0
           submodules: recursive