config.mak.uname: avoid macOS dup-library warning

config.mak.uname: avoid macOS dup-library warning

Building on macOS with Xcode 15 or newer emits:

    ld: warning: ignoring duplicate libraries: 'libgit.a',
    'target/release/libgitcore.a'

Some link recipes list the same archive twice, which is harmless.
Quiet the warning instead.

Pass -Wl,-no_warn_duplicate_libraries on Xcode 15 and newer, whose
linkers added both the warning and the suppression flag (ld64-907
and dyld-1009). Earlier linkers reject the flag, so gate on the
linker version. Broaden the existing -fno-common version probe to
also match the "ld64-NNN" and "dyld-NNN" forms Xcode 15 reports.

Signed-off-by: Harald Nordgren <haraldnordgren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>