Actions: Shard test suite (#105166)

.github/workflows/backend-unit-tests.yml

@@ -24,7 +24,15 @@ jobs:
     # Run this workflow only for PRs from forks; if it gets merged into `main` or `release-*`, 
     # the `pr-backend-unit-tests-enterprise` workflow will run instead
     if: github.event_name == 'pull_request' && github.event.pull_request.head.repo.fork == true
-    name: Grafana
+    strategy:
+      matrix:
+        shard: [
+          1/8, 2/8, 3/8, 4/8,
+          5/8, 6/8, 7/8, 8/8,
+        ]
+      fail-fast: false
+
+    name: Grafana (${{ matrix.shard }})
     runs-on: ubuntu-latest-8-cores
     continue-on-error: true
     permissions:
@@ -42,12 +50,24 @@ jobs:
       - name: Generate Go code
         run: make gen-go
       - name: Run unit tests
-        run: make test-go-unit
+        env:
+          SHARD: ${{ matrix.shard }}
+        run: |
+          readarray -t PACKAGES <<< "$(./scripts/ci/backend-tests/shard.sh -N"$SHARD")"
+          go test -short -timeout=30m "${PACKAGES[@]}"
 
   grafana-enterprise:
     # Run this workflow for non-PR events (like pushes to `main` or `release-*`) OR for internal PRs (PRs not from forks)
     if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.fork == false
-    name: Grafana Enterprise
+    strategy:
+      matrix:
+        shard: [
+          1/8, 2/8, 3/8, 4/8,
+          5/8, 6/8, 7/8, 8/8,
+        ]
+      fail-fast: false
+
+    name: Grafana Enterprise (${{ matrix.shard }})
     runs-on: ubuntu-latest-8-cores
     permissions:
       contents: read
@@ -68,4 +88,8 @@ jobs:
       - name: Generate Go code
         run: make gen-go
       - name: Run unit tests
-        run: make test-go-unit
+        env:
+          SHARD: ${{ matrix.shard }}
+        run: |
+          readarray -t PACKAGES <<< "$(./scripts/ci/backend-tests/shard.sh -N"$SHARD")"
+          go test -short -timeout=30m "${PACKAGES[@]}"