Fix CI: install Clojure manually instead of using GitHub action

The DeLaGuardo/setup-clojure action requires GitHub credentials
which aren't available in Gitea Actions.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/workflows/scip-index.yml

@@ -11,21 +11,15 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Setup Clojure
-        uses: DeLaGuardo/setup-clojure@12.5
-        with:
-          cli: latest
+      - name: Setup Java
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y openjdk-17-jdk
+          echo "JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64" >> $GITHUB_ENV
 
-      - name: Cache Clojure dependencies
-        uses: actions/cache@v4
-        with:
-          path: |
-            ~/.m2/repository
-            ~/.gitlibs
-            ~/.clojure
-          key: ${{ runner.os }}-clojure-${{ hashFiles('**/deps.edn') }}
-          restore-keys: |
-            ${{ runner.os }}-clojure-
+      - name: Install Clojure CLI
+        run: |
+          curl -fsSL https://download.clojure.org/install/linux-install-1.12.0.1501.sh | sudo bash
 
       - name: Install clojure-lsp
         run: |