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

v13.2, as used for the build. This should fix this error:
```
/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').

Author: kinke

.github/workflows/test_release.yml

@@ -74,7 +74,7 @@ jobs:
           hypervisor: qemu
           memory: 12G
           cpu_count: 4
-          version: '12.2'
+          version: '13.2'
           environment_variables: OS BUILD
           shell: bash
           run: source ./installer/test/release/validate_release.sh