Check unused modules for changed files only

We always run this check for all modules in the repo, which takes around
5 minutes. However, we can just check files which are changed in the
  repo.
For that we have 3 cases:
1. Module is added or renamed
2. Last usage is removed from main.pm
3. Last usage is removed from any schedule file

With this change, we get modules from each of the group and verify if
they are used anywhere else and fail CI check in case it's not.

See [poo#64688](https://progress.opensuse.org/issues/64688).

Makefile

@@ -128,7 +128,9 @@ perlcritic: tools/lib/
 
 .PHONY: test-unused-modules
 test-unused-modules:
-	tools/detect_unused_modules
+	tools/detect_unused_modules `git diff --name-only --diff-filter=d $$(git merge-base master HEAD) | grep '^tests/*'`
+	tools/detect_unused_modules `git diff --unified=0 $$(git merge-base master HEAD) products/* | grep -oP "^-.*loadtest.*[\"']\K[^\"'].+(?=[\"'])"`
+	tools/detect_unused_modules `git diff --unified=0 $$(git merge-base master HEAD) schedule/* | grep -oP "^-\s+- [\"']?\K.*(?=[\"']?)" | grep -v '{{'`
 
 .PHONY: test-deleted-renamed-referenced-files
 test-deleted-renamed-referenced-files:

tools/detect_unused_modules

@@ -1,9 +1,11 @@
 #!/bin/sh -e
 
-for test in $(git ls-files "*tests/*.pm") ; do
+MODULES="${@}"
+
+for test in $MODULES ; do
     t=$(echo $test | sed -e 's@tests/.*/@@' -e 's@\.pm$@@')
     t_dir=$(echo $test | sed -e 's@tests/\(.*\)/.*$@\1@')
-    git grep -E "(- $t_dir/$t|loadtest.*$t|load_testdir.*$t_dir|^use (base )?\"?$t\"?)" | grep -qv ".(pm|yaml):\s*#" || echo $test
+    git grep -E "(- $t_dir/$t|loadtest.*$t|load_testdir.*$t_dir|^use (base )?\"?$t\"?)" | grep -qv ".(pm|yaml):\s*#" || echo "$test module is not used in any schedule"
 done | \
     # Whitelist