CI: always run set-matrix to prevent locked up PRs on docs

Letting `set_matrix` job run always, because it is required to report its
status for an approved PR to be merged.

Fixes: #571

Author: NeroBurner

.github/workflows/ci.yml

@@ -1,9 +1,7 @@
 name: CI
 on:
   push:
-    paths: [ 'cmake/projects/**' ]
   pull_request:
-    paths: [ 'cmake/projects/**' ]
   workflow_dispatch:
     inputs:
       project: