ci: use self-hosted agent for packaging

WIP.

.github/workflows/build-release-artifacts.yml

@@ -23,6 +23,16 @@ env:
   PAYMENT_FORWARD_PK: ${{ secrets.STABLE_REWARD_FORWARDING_PK }}
 
 jobs:
+  test:
+    name: build
+    runs-on: self-hosted
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.tag || inputs.branch }}
+      - shell: bash
+        run: just build-release-artifacts "x86_64-unknown-linux-musl"
+
   build:
     name: build
     runs-on: ${{ matrix.os }}
@@ -61,11 +71,9 @@ jobs:
             artifacts
             !artifacts/.cargo-lock
 
-  # This job isn't necessary, but it's useful for debugging the packaging process for the real release
-  # workflow, just in case any issues are ever encountered there.
   package:
     name: package artifacts
-    runs-on: ubuntu-latest
+    runs-on: self-hosted
     needs: [build]
     steps:
       - uses: actions/checkout@v4