ci(go.mod): verify go.mod and go.sum don't have uncommitted changes after go mod tidy (#1287)

This is to avoid situations such as https://github.com/project-zot/zot/pull/1150
where an indirect dependency became direct without a corresponding go.mod change

Signed-off-by: Andrei Aaron <aaaron@luxoft.com>

Makefile

@@ -36,10 +36,19 @@ extended-name:=
 .PHONY: all
 all: modcheck swagger binary binary-minimal binary-debug cli bench exporter-minimal verify-config test covhtml check check-gh-actions
 
-.PHONY: modcheck
-modcheck:
+.PHONY: modtidy
+modtidy:
 	go mod tidy
 
+.PHONY: modcheck
+modcheck: modtidy
+	$(eval UNCOMMITED_FILES = $(shell git status --porcelain | grep -c 'go.mod\|go.sum'))
+	@if [ $(UNCOMMITED_FILES) != 0 ]; then \
+		echo "Updated go.mod and/or go.sum have uncommitted changes, commit the changes accordingly ";\
+		git status;\
+		exit 1;\
+	fi
+
 .PHONY: create-name
 create-name:
 ifdef EXTENSIONS