build(deps): bump actions/github-script from 6 to 8

Bumps [actions/github-script](https://github.com/actions/github-script) from 6 to 8.
- [Release notes](https://github.com/actions/github-script/releases)
- [Commits](actions/github-script@v6...v8)

---
updated-dependencies:
- dependency-name: actions/github-script
  dependency-version: '8'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/kani-regression.yml

@@ -312,7 +312,7 @@ jobs:
 
     - name: Comment PR with results
       if: github.event_name == 'pull_request'
-      uses: actions/github-script@v7
+      uses: actions/github-script@v8
       with:
         script: |
           const fs = require('fs');

.github/workflows/kani-verification.yml

@@ -221,7 +221,7 @@ jobs:
 
       - name: Comment PR with Results
         if: github.event_name == 'pull_request'
-        uses: actions/github-script@v7
+        uses: actions/github-script@v8
         with:
           script: |
             const fs = require('fs');

.github/workflows/pr-diagnostics.yml

@@ -356,7 +356,7 @@ jobs:
         retention-days: 30
 
     - name: Comment on PR
-      uses: actions/github-script@v6
+      uses: actions/github-script@v8
       with:
         script: |
           const fs = require('fs');
@@ -393,7 +393,7 @@ jobs:
           }
           
     - name: Set check status
-      uses: actions/github-script@v6
+      uses: actions/github-script@v8
       with:
         script: |
           const errorsChanged = ${{ steps.diff-analysis.outputs.new_errors_changed }};