blast_repo fixes (dart-lang/test_reflective_loader#42)

Dependabot
GitHub Action
diff --git a/pkgs/test_reflective_loader/.github/dependabot.yml b/pkgs/test_reflective_loader/.github/dependabot.yml
new file mode 100644
index 0000000..1603cdd
--- /dev/null
+++ b/pkgs/test_reflective_loader/.github/dependabot.yml
@@ -0,0 +1,9 @@
+# Dependabot configuration file.
+# See https://docs.github.com/en/code-security/dependabot/dependabot-version-updates
+version: 2
+
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "monthly"
diff --git a/pkgs/test_reflective_loader/.github/workflows/build.yaml b/pkgs/test_reflective_loader/.github/workflows/build.yaml
index 9728c94..10913c6 100644
--- a/pkgs/test_reflective_loader/.github/workflows/build.yaml
+++ b/pkgs/test_reflective_loader/.github/workflows/build.yaml
@@ -21,8 +21,8 @@
         sdk: [dev, stable]
 
     steps:
-      - uses: actions/checkout@v2
-      - uses: dart-lang/setup-dart@v1
+      - uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8
+      - uses: dart-lang/setup-dart@6a218f2413a3e78e9087f638a238f6b40893203d
         with:
           sdk: ${{ matrix.sdk }}