ci(deps): bump actions/download-artifact from 7 to 8 (#128)

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 7 to 8.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v7...v8)

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

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

@@ -166,7 +166,7 @@ jobs:
         uses: actions/checkout@v6
 
       - name: Download coverage from test job
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: test-results-ubuntu-latest-go1.24
           path: ./coverage-download
@@ -269,7 +269,7 @@ jobs:
     continue-on-error: true  # Don't fail the whole pipeline on coverage issues
     steps:
       - name: Download coverage reports
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: coverage-reports
           path: ./
@@ -398,7 +398,7 @@ jobs:
           go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
           
       - name: Download binaries
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: plugin-binaries
           path: bin/