Github actions run .tpl file generation (type-checker) 3 times instead of once

[jurgenvinju]

Describe the bug

We run the type-checker 3 times on the standard library, each run costs almost on hour on github actions.

• as mentioned by @DavyLandman here: https://github.com/usethesource/rascal/issues/1562#issuecomment-995861711
• a combination of behavior of rascal-maven-plugin, pom.xml of the rascal project and github workflow configuration of the rascal project leads to this behavior

[jurgenvinju]

One can be fixed, but the other is problematic. In particular:

6270 [INFO] stale source files have been found:

during the artifact stage is strange. How could the source files be stale if we just compiled everything. This points to a possible new issue in the rascal-maven-plugin