update and pin github actions (#1536)

Author: bashbaug

.github/workflows/presubmit.yml

@@ -20,7 +20,7 @@ jobs:
     container: khronosgroup/docker-images@sha256:4aab96a03ef292439c9bd0f972adfa29cdf838d0909b1cb4ec2a6d7b2d14a37f
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           submodules: recursive
           # If fetch-depth: 0 is not specified, then

.github/workflows/release.yml

@@ -22,7 +22,7 @@ jobs:
 
     steps:
       - name: Get Spec Source
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.2.2
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           submodules: recursive
           # If fetch-depth: 0 is not specified, then