[GLib] Drop support for GNU Autotools

[asfimport]

If we drop support for GNU Autotools, we can simplify our source archive release process.

Reporter: Kouhei Sutou / @kou
Assignee: Kouhei Sutou / @kou

PRs and other links:

• GitHub Pull Request #9787

_{Note: This issue was originally created as ARROW-12070. Please see the migration documentation for further details.}

[asfimport]

Kouhei Sutou / @kou:
Issue resolved by pull request 9787
#9787