ci: manually define vars for lint build

Git in containerised workflows doesn't really like to work properly, so
avoid using it by manually defining variables

.github/workflows/lint.yml

@@ -18,8 +18,8 @@ jobs:
 
       - name: Build
         run: |
-          # Use fake version for CI build
-          cmake -B build -G Ninja -DCMAKE_CXX_COMPILER=clazy -DCMAKE_CXX_FLAGS=-Werror -DVERSION=v0.0.0
+          # Set version and git rev for CI build so we don't call git
+          cmake -B build -G Ninja -DCMAKE_CXX_COMPILER=clazy -DCMAKE_CXX_FLAGS=-Werror -DVERSION= -DGIT_REVISION=
           cmake --build build
 
       - name: Lint QML