CI: run make all before checking for uncommitted changes

Currently, `make test` is used to detect uncommitted file changes, but
it missed some targets that modify files (e.g. "make docs").
Update the workflow to also run `make all`, to ensure that all relevant
file-generating targets are executed before checking for uncommitted
changes.

Refs: https://issues.redhat.com/browse/EC-1262

Author: Acepresso

.github/workflows/checks.yaml

@@ -35,6 +35,9 @@ jobs:
       - name: Check go versions
         uses: enterprise-contract/github-workflows/golang-version-check@main
 
+      - name: Build all
+        run: make all
+
       - name: Test
         run: make test
 
@@ -69,6 +72,7 @@ jobs:
           if ! git diff --exit-code -s; then
             for f in $(git diff --exit-code --name-only); do
               echo "::error file=$f,line=1,col=1,endColumn=1::File was modified in build"
+              echo -e "\033[1;33mHint:\033[0m Maybe you need to run \033[1;32mmake all\033[0m"
             done
             exit 1
           fi