Bump actions/upload-artifact from 5 to 6

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v5...v6)

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

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

Author: dependabot[bot]

.github/workflows/build_and_test.yml

@@ -129,7 +129,7 @@ jobs:
       shell: bash
 
     - name: Save report
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v6
       if: matrix.os == 'ubuntu-latest' && matrix.compiler == 'gcc' && matrix.cxx_stdlib == 'libstdc++' && matrix.asio_type == 'boost' && !startsWith(github.ref, 'refs/tags/v')
       with:
         name: coveralls.json
@@ -149,7 +149,7 @@ jobs:
           md5sum "$f"    | awk '{print $1}' > "$f".md5
         done
 
-    - uses: actions/upload-artifact@v5
+    - uses: actions/upload-artifact@v6
       if: matrix.os == 'ubuntu-latest' && matrix.compiler == 'gcc' && matrix.cxx_stdlib == 'libstdc++' && matrix.asio_type == 'boost' && startsWith(github.ref, 'refs/tags/v')
       with:
         name: packages

.github/workflows/cifuzz.yml

@@ -25,7 +25,7 @@ jobs:
         fuzz-seconds: 800
         output-sarif: true
     - name: Upload Crash
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v6
       if: failure() && steps.build.outcome == 'success'
       with:
         name: artifacts