fix: use git clone instead of actions/checkout for sibling repos (#1609)

actions/checkout@v4 rejects paths outside the repository root
(error: 'Repository path is not under ...'), so checking out
vscode-java and eclipse.jdt.ls as siblings with path: ../repo fails.

Replace with 'git clone --depth 1' which has no path restriction,
correctly placing repos as siblings so test plan relative paths
(../../vscode-java/...) resolve properly.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: wenytang-ms

.github/workflows/e2e-autotest.yml

@@ -47,17 +47,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Checkout vscode-java (test projects)
-        uses: actions/checkout@v4
-        with:
-          repository: redhat-developer/vscode-java
-          path: ../vscode-java
+      - name: Clone vscode-java (test projects)
+        run: git clone --depth 1 https://github.com/redhat-developer/vscode-java.git ../vscode-java
 
-      - name: Checkout eclipse.jdt.ls (Gradle test projects)
-        uses: actions/checkout@v4
-        with:
-          repository: eclipse-jdtls/eclipse.jdt.ls
-          path: ../eclipse.jdt.ls
+      - name: Clone eclipse.jdt.ls (Gradle test projects)
+        run: git clone --depth 1 https://github.com/eclipse-jdtls/eclipse.jdt.ls.git ../eclipse.jdt.ls
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
@@ -133,17 +127,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Checkout vscode-java
-        uses: actions/checkout@v4
-        with:
-          repository: redhat-developer/vscode-java
-          path: ../vscode-java
+      - name: Clone vscode-java
+        run: git clone --depth 1 https://github.com/redhat-developer/vscode-java.git ../vscode-java
 
-      - name: Checkout eclipse.jdt.ls
-        uses: actions/checkout@v4
-        with:
-          repository: eclipse-jdtls/eclipse.jdt.ls
-          path: ../eclipse.jdt.ls
+      - name: Clone eclipse.jdt.ls
+        run: git clone --depth 1 https://github.com/eclipse-jdtls/eclipse.jdt.ls.git ../eclipse.jdt.ls
 
       - name: Setup Node.js
         uses: actions/setup-node@v4