Update all third-party GitHub Actions to v6

Author: renovate[bot]

.github/workflows/build.yml

@@ -22,7 +22,7 @@ jobs:
       contents: write
     steps:
       - &checkout-simple
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
       - &mise-install
         uses: jdx/mise-action@9dc7d5dd454262207dea3ab5a06a3df6afc8ff26 # v3.4.1
         with:
@@ -141,7 +141,7 @@ jobs:
         SQ_VERSION: [LATEST_RELEASE, DEV]
     steps:
       - &checkout-submodules
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
           submodules: true
       - *mise-install

.github/workflows/bump-versions.yaml

@@ -20,7 +20,7 @@ jobs:
       contents: write # write for peter-evans/create-pull-request, read for actions/checkout
       pull-requests: write # write for peter-evans/create-pull-request
     steps:
-      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
       - env:
           VERSION: ${{ inputs.version }}
         run: |

.github/workflows/shadow_scan.yml

@@ -18,7 +18,7 @@ jobs:
     name: Build
     if: github.event_name != 'pull_request' || contains(github.event.pull_request.labels.*.name, 'shadow_scan')
     steps:
-      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
       - uses: jdx/mise-action@9dc7d5dd454262207dea3ab5a06a3df6afc8ff26 # v3.4.1
         with:
           version: 2025.7.12