Upgrade GitHub Actions for Node 24 compatibility (#247)

Signed-off-by: Salman Muin Kayser Chishti <13schishti@gmail.com>
diff --git a/.github/workflows/verify-pull-request.yml b/.github/workflows/verify-pull-request.yml
index 744b5c9..090d1e1 100644
--- a/.github/workflows/verify-pull-request.yml
+++ b/.github/workflows/verify-pull-request.yml
@@ -10,7 +10,7 @@
         cpp-compiler: ["clang", "gcc"]
         options: ["-c opt", ""]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: bazel-contrib/setup-bazel@0.8.5
         with:
           bazelisk-cache: true
@@ -22,7 +22,7 @@
     name: "Check Python formatting"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: psf/black@stable
         with:
           options: "--check --verbose"
@@ -31,7 +31,7 @@
     name: "Check build.json"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: bazel-contrib/setup-bazel@0.8.5
         with:
           bazelisk-cache: true