github actions: Add kabi checks

LE-3801

After the build check, perform a kabi check

Author: bmastbergen

.github/workflows/build-check_x86_64.yml

@@ -32,3 +32,8 @@ jobs:
           cp configs/kernel-x86_64.config .config
           make olddefconfig
           make -j8
+      - name: Check kabi
+        run: |
+          git clone --branch r8 --single-branch https://git.rockylinux.org/staging/rpms/kernel.git kernel-dist-git
+          git -C kernel-dist-git reset --hard imports/r8/kernel-4.18.0-425.13.1.el8_7
+          ./kernel-dist-git/SOURCES/check-kabi -k ./kernel-dist-git/SOURCES/Module.kabi_x86_64 -s Module.symvers