Bump the all group across 1 directory with 4 updates (#579)

Bumps the all group with 4 updates in the / directory: [actions/checkout](https://github.com/actions/checkout), [actions/upload-artifact](https://github.com/actions/upload-artifact), [actions/cache](https://github.com/actions/cache) and [peter-evans/create-pull-request](https://github.com/peter-evans/create-pull-request).


Updates `actions/checkout` from 4 to 6
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v6)

Updates `actions/upload-artifact` from 4 to 6
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v6)

Updates `actions/cache` from 4 to 5
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v4...v5)

Updates `peter-evans/create-pull-request` from 7 to 8
- [Release notes](https://github.com/peter-evans/create-pull-request/releases)
- [Commits](peter-evans/create-pull-request@v7...v8)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: all
- dependency-name: actions/upload-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: all
- dependency-name: actions/cache
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: all
- dependency-name: peter-evans/create-pull-request
  dependency-version: '8'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: all
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
       LINUX_BOOGIE_URL: "https://github.com/viperproject/boogie-builder/releases/download/7449a7a899c02c95/boogie-linux.zip"
     steps:
     - name: Checkout Carbon
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         submodules: true
     - name: Java Version
@@ -30,7 +30,7 @@ jobs:
         echo "Silver: commit $(git -C silver rev-parse HEAD)" >> versions.txt
       # first line overwrites versions.txt in case it already exists, all other append to the file
     - name: Upload version file
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: versions-${{ matrix.name }}.txt
         path: versions.txt
@@ -40,7 +40,7 @@ jobs:
       # note that the cache path is relative to the directory in which sbt is invoked.
 
     - name: Cache SBT
-      uses: actions/cache@v4
+      uses: actions/cache@v5
       with:
         path: |
           sbt-cache/.sbtboot
@@ -67,7 +67,7 @@ jobs:
       run: sbt "set test in assembly := {}" clean assembly
 
     - name: Upload Carbon fat JAR
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: carbon-jar
         path: target/scala-2.13/carbon.jar

.github/workflows/update-submodules.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out the repo
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           submodules: true
 
@@ -41,7 +41,7 @@ jobs:
 
       - name: Open a pull request
         id: pr
-        uses: peter-evans/create-pull-request@v7
+        uses: peter-evans/create-pull-request@v8
         if: (env.PREV_SILVER_REF != env.CUR_SILVER_REF)
         with:
           # Use viper-admin's token to workaround a restriction of GitHub.