[stable] CI: Fix verification on FreeBSD by switching to the same FreeBSD version

[kinke]

v13.2, as used for the build:

installer/.github/workflows/build_release_template.yml

Line 275 in 40bc9ab

version: '13.2'

This should fix this error (https://github.com/dlang/installer/actions/runs/22625401992/job/65562732407#step:5:101):

/home/runner/work/installer/installer/installer/test/release/generated/dmd2/freebsd/bin64/dmd --version
ld-elf.so.1: /lib/libc.so.7: version FBSD_1.7 required by /home/runner/work/installer/installer/installer/test/release/generated/dmd2/freebsd/bin64/dmd not found

FreeBSD 13 is the oldest still supported version ('legacy'): https://www.freebsd.org/releases/

[dlang-bot]

Thanks for your pull request and interest in making D better, @kinke! We are looking forward to reviewing it, and you should be hearing from a maintainer soon.
Please verify that your PR follows this checklist:

• My PR is fully covered with tests (you can see the coverage diff by visiting the details link of the codecov check)
• My PR is as minimal as possible (smaller, focused PRs are easier to review than big ones)
• I have provided a detailed rationale explaining my changes
• New or modified functions have Ddoc comments (with Params: and Returns:)

Please see CONTRIBUTING.md for more information.

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