Don't underlink inputtest on targets which require complete linkage

Don't underlink inputtest on targets which require complete linkage
(e.g. when building for PE/COFF)
5 jobs for inputtest-linkage in 4 minutes and 48 seconds (queued for 10 seconds)
Status Name Job ID Coverage
  Docker Image
passed debian-buster #13298961

00:00:12

 
  Build And Test
passed autotools #13298962

00:04:35

passed meson #13298963

00:01:57

passed meson-noglamor #13298964

00:02:12

passed mingw-cross-build #13298965

00:00:55