chore(deps): bump actions/download-artifact in /.github/workflows

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

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

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

Author: dependabot[bot]

.github/workflows/library_interop_tests.yml

@@ -409,7 +409,7 @@ jobs:
           make purge_polymorph_code
 
       - name: Download Encrypt Manifest Artifact Java
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v6
         with:
           name: ${{matrix.os}}_vector_artifact_java${{ inputs.fuzz-testing && '_fuzz' || '' }}
           path: ./${{matrix.library}}/runtimes/${{matrix.decrypting_language}}
@@ -419,7 +419,7 @@ jobs:
         run: make test_decrypt_encrypt_vectors_${{matrix.decrypting_language}}
 
       - name: Download Encrypt Manifest Artifact Net
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v6
         with:
           name: ${{matrix.os}}_vector_artifact_net${{ inputs.fuzz-testing && '_fuzz' || '' }}
           path: ./${{matrix.library}}/runtimes/${{matrix.decrypting_language}}
@@ -429,7 +429,7 @@ jobs:
         run: make test_decrypt_encrypt_vectors_${{matrix.decrypting_language}}
 
       - name: Download Encrypt Manifest Artifact Rust
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v6
         with:
           name: ${{matrix.os}}_vector_artifact_rust${{ inputs.fuzz-testing && '_fuzz' || '' }}
           path: ./${{matrix.library}}/runtimes/${{matrix.decrypting_language}}
@@ -439,7 +439,7 @@ jobs:
         run: make test_decrypt_encrypt_vectors_${{matrix.decrypting_language}}
 
       - name: Download Encrypt Manifest Artifact Python
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v6
         with:
           name: ${{matrix.os}}_vector_artifact_python${{ inputs.fuzz-testing && '_fuzz' || '' }}
           path: ./${{matrix.library}}/runtimes/${{matrix.decrypting_language}}
@@ -449,7 +449,7 @@ jobs:
         run: make test_decrypt_encrypt_vectors_${{matrix.decrypting_language}}
 
       - name: Download Encrypt Manifest Artifact Go
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v6
         with:
           name: ${{matrix.os}}_vector_artifact_go${{ inputs.fuzz-testing && '_fuzz' || '' }}
           path: ./${{matrix.library}}/runtimes/${{matrix.decrypting_language}}