meson: stop setting the linker (#6182)

If wanted, the linker can be set with LDFLAGS (LDFLAGS=-Wl,-fuse-ld=gold meson ...),
and setting it internally was interfering with that. It seems that both gold and
bfd work very well and quick, and the reasons we had to prefer gold are not relevant
anymore.

Fixes #6169.

meson.build

@@ -312,7 +312,6 @@ link_test_c = files('tools/meson-link-test.c')
 foreach arg : ['-Wl,-z,relro',
                '-Wl,-z,now',
                '-pie',
-               '-Wl,-fuse-ld=gold',
               ]
 
         have = run_command(check_compilation_sh,