blast_repo fixes (dart-lang/stack_trace#123)

Dependabot
GitHub Action

pkgs/stack_trace/.github/dependabot.yml

diff --git a/pkgs/stack_trace/.github/dependabot.yml b/pkgs/stack_trace/.github/dependabot.yml
new file mode 100644
index 0000000..9523511
--- /dev/null
+++ b/pkgs/stack_trace/.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

pkgs/stack_trace/.github/workflows/test-package.yml

diff --git a/pkgs/stack_trace/.github/workflows/test-package.yml b/pkgs/stack_trace/.github/workflows/test-package.yml
index 23916f3..1149cbb 100644
--- a/pkgs/stack_trace/.github/workflows/test-package.yml
+++ b/pkgs/stack_trace/.github/workflows/test-package.yml
@@ -22,7 +22,7 @@
       matrix:
         sdk: [dev]
     steps:
-      - uses: actions/checkout@2541b1294d2704b0964813337f33b291d3f8596b
+      - uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8
       - uses: dart-lang/setup-dart@6a218f2413a3e78e9087f638a238f6b40893203d
         with:
           sdk: ${{ matrix.sdk }}
@@ -49,7 +49,7 @@
         os: [ubuntu-latest]
         sdk: [2.18.0, dev]
     steps:
-      - uses: actions/checkout@2541b1294d2704b0964813337f33b291d3f8596b
+      - uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8
       - uses: dart-lang/setup-dart@6a218f2413a3e78e9087f638a238f6b40893203d
         with:
           sdk: ${{ matrix.sdk }}