Bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -70,18 +70,18 @@ jobs:
           git config --global core.autocrlf false
           git config --global core.eol lf
       - name: Checkout sbt/sbt
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
           submodules: true
       - name: Checkout sbt/io
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: sbt/io
           ref: develop
           path: io
       - name: Checkout sbt/zinc
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: sbt/zinc
           ref: develop

.github/workflows/client-test.yml

@@ -28,7 +28,7 @@ jobs:
       SBT_ETC_FILE: $HOME/etc/sbt/sbtopts
       TEST_SBT_VER: 1.11.4
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Setup JDK
       uses: actions/setup-java@v5
       with:

.github/workflows/dependency-graph.yml

@@ -12,6 +12,6 @@ jobs:
     name: Submit Dependency Graph
     runs-on: ubuntu-latest # or windows-latest, or macOS-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: sbt/setup-sbt@v1
       - uses: scalacenter/sbt-dependency-submission@v3

.github/workflows/nightly.yml

@@ -21,15 +21,15 @@ jobs:
       JAVA_OPTS: -Xms800M -Xmx800M -Xss6M -XX:ReservedCodeCacheSize=128M -server -Dsbt.io.virtual=false -Dfile.encoding=UTF-8
     steps:
     - name: Checkout sbt/sbt
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Checkout sbt/io
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         repository: sbt/io
         ref: develop
         path: io
     - name: Checkout sbt/zinc
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         repository: sbt/zinc
         ref: develop

.github/workflows/server-test.yml

@@ -14,7 +14,7 @@ jobs:
       JVM_OPTS: -Xms800M -Xmx2G -Xss6M -XX:ReservedCodeCacheSize=128M -server -Dsbt.io.virtual=false -Dfile.encoding=UTF-8
       SBT_ETC_FILE: $HOME/etc/sbt/sbtopts
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Setup JDK
       uses: actions/setup-java@v5
       with: