ci: Change PATH var

Due to update of toolchain container, fasm in /home/autobuild/... folder

.gitea/workflows/build.yaml

@@ -75,10 +75,9 @@ jobs:
           chmod +x /home/autobuild/tools/win32/bin/objconv
 
       - name: Build and install kerpack
-        environment:
-          PATH: /home/autobuild/tools/win32/bin:$PATH
         if: steps.cache-toolchain.outputs.cache-hit != 'true'
         run: |
+          export PATH=/home/autobuild/tools/win32/bin:$PATH
           cd ${{ gitea.workspace }}/programs/other/kpack/kerpack_linux/
           make
           chmod +x kerpack