fix(ci): use self-hosted runner for unit tests (private repo)

GitHub-hosted runners (ubuntu-latest, etc.) are not available for
private repos without paid Actions minutes. Reverts the matrix to
run on the self-hosted macOS runner while keeping the 3-job split
that deduplicates unit test runs.

Signed-off-by: Sebastien Tardif <sebtardif@ncf.ca>

Author: SebTardif

.github/workflows/ci.yml

@@ -14,11 +14,11 @@ concurrency:
 
 jobs:
   unit-test:
-    strategy:
-      fail-fast: false
-      matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
-    runs-on: ${{ matrix.os }}
+    runs-on:
+      - self-hosted
+      - macOS
+      - ARM64
+      - patchloom-vscode
     timeout-minutes: 10
     steps:
       - name: Checkout