github actions: build-check: Use ./scripts/dummy-tools/ for olddefconfig

LE-2788

This prevents any local machine particulars from changing the config

Author: bmastbergen

.github/workflows/build-check_aarch64.yml

@@ -30,5 +30,5 @@ jobs:
         run: |
           git config --global --add safe.directory /__w/kernel-src-tree/kernel-src-tree
           cp configs/kernel-aarch64-rhel.config .config
-          make olddefconfig
+          make ARCH=arm64 CROSS_COMPILE=./scripts/dummy-tools/ olddefconfig
           make -j8

.github/workflows/build-check_x86_64.yml

@@ -30,5 +30,5 @@ jobs:
         run: |
           git config --global --add safe.directory /__w/kernel-src-tree/kernel-src-tree
           cp configs/kernel-x86_64-rhel.config .config
-          make olddefconfig
+          make ARCH=x86_64 CROSS_COMPILE=./scripts/dummy-tools/ olddefconfig
           make -j8