base.yml: Set CGO flags

[livingsilver94]

These are used when compiling cgo packages.

Couple of notes:

• Why TERM="dumb"; export TERM instead of just export TERM="dumb"? I thought it's because set -x doesn't print the expanded variable but it does, according to a test.
• CGO flags aren't inherited from standard flags, so these are necessary.
• In the future we may have more flags: Fortran, Rust, Zig and whatnot. IMO it's wise to split the base script into multiple and single-scoped portions.

[ermo]

• Why TERM="dumb"; export TERM instead of just export TERM="dumb"? I thought it's because set -x doesn't print the expanded variable but it does, according to a test.

Because it's easier for the eye to scan for differences that way; otherwise, everything would start with export.

[ermo]

• In the future we may have more flags: Fortran, Rust, Zig and whatnot. IMO it's wise to split the base script into multiple and single-scoped portions.

May want to put this in an issue so we don't forget?

[ermo]

LGTM, thanks!