Bump actions/upload-artifact from 5 to 6 (#358)

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

Author: dependabot[bot]

.github/workflows/maven-build.yml

@@ -22,7 +22,7 @@ jobs:
       - name: Build with Maven
         run: mvn -B package
       - name: Upload artifact
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           name: "BetterGUI"
           path: "./target/bettergui*.jar"

.github/workflows/maven-release.yml

@@ -27,7 +27,7 @@ jobs:
         run: mvn -B install javadoc:javadoc
 
       - name: Upload artifact
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           name: "BetterGUI"
           path: |