ci: remove explicit develocity key

Ad the short-lived access key seems to have been fetched, this commit removes the explicit setting of the `DEVELOCITY_ACCESS_KEY` environment variable.

.github/workflows/gradle.yml

@@ -36,14 +36,10 @@ jobs:
       - name: "🏃 Run Tests"
         if: github.event_name == 'pull_request'
         id: tests
-        env:
-          DEVELOCITY_ACCESS_KEY: ${{ secrets.DEVELOCITY_ACCESS_KEY }}
         run: ./gradlew check
       - name: "🔨 Build project"
         if: github.event_name == 'push'
         id: build
-        env:
-          DEVELOCITY_ACCESS_KEY: ${{ secrets.DEVELOCITY_ACCESS_KEY }}
         run: ./gradlew build
       - name: "📄 Publish Test Report"
         if: steps.build.outcome == 'failure' || steps.tests.outcome == 'failure'
@@ -60,8 +56,6 @@ jobs:
       - name: "✍️ Generate Documentation"
         id: docs
         if: success() && github.event_name == 'push' && matrix.java == '17'
-        env:
-          DEVELOCITY_ACCESS_KEY: ${{ secrets.DEVELOCITY_ACCESS_KEY }}
         run: ./gradlew docs
       - name: "📤 Publish to Github Pages"
         if: steps.publish.outcome == 'success' && github.event_name == 'push' && matrix.java == '17'