[Bug 56469] New: configure incorrectly setting ac_cv_lib_soname_vulkan value on macOS

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56469

Bug ID: 56469
           Summary: configure incorrectly setting ac_cv_lib_soname_vulkan
                    value on macOS
           Product: Wine
           Version: 9.5
          Hardware: x86-64
                OS: MacOS
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: -unknown
          Assignee: [e-mail]
          Reporter: [e-mail]
                CC: [e-mail]
   Regression SHA1: 1ddaa1d385c804f2af9bb16d2c5082122132f09b

Currently ac_cv_lib_soname_vulkan gets set as libMoltenVK this causes
> dlls/win32u/vulkan.c:93:37: error: use of undeclared identifier 'libMoltenVK'

This should be getting set to libMoltenVK.dylib