In GitHub Actions I installed `sudo apt install gdc-12` now
inside Ubuntu 22.04, however `gdc` still seemed to be a small
extra package that's symlinking gdc to gdc-11.
Now gdmd is picking up GDC 11 instead of GDC 12, causing issues
in the build.
Is there a way to tell gdmd to use GDC 12? Right now I hacked
around this by doing
```
sudo rm /usr/bin/gdc
sudo ln -s /usr/bin/gdc-12 /usr/bin/gdc
```
but if this wasn't a CI, I wouldn't really wanna do this.
Would it be possible to provide extra gdmd scripts like gdmd-12
that pick gdc-12 on Ubuntu?
see commit
https://github.com/dlang-community/libdparse/commit/03099519982c10b9d7831771bcb744f06b727400
Since this is manual DMD invocation, and not dub, I can't just
specify gdc-12 as compiler.
