.github: Fix CI workflows to checkout libbpf

Signed-off-by: Dave Tucker <dave@dtucker.co.uk>

.github/workflows/gen.yml

@@ -8,6 +8,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v3
+      - uses: actions/checkout@v3
+        with:
+          repository: libbpf/libbpf
+          path: libbpf
 
       - name: libbpf-version
         working-directory: libbpf

.github/workflows/integration-tests.yml

@@ -17,9 +17,11 @@ jobs:
     runs-on: macos-latest
 
     steps:
+      - uses: actions/checkout@v3
       - uses: actions/checkout@v3
         with:
-          submodules: recursive
+          repository: libbpf/libbpf
+          path: libbpf
 
       - name: Install Pre-requisites
         run: |