libayatana-indicator: Fix build with glib2 +quartz

[thestr4ng3r]

Description

The gdesktopappinfo.h header does not exist in glib2 +quartz, but is also not needed by libayatana-indicator. See also AyatanaIndicators/libayatana-indicator#77

Type(s)

• bugfix
• enhancement
• security fix

Tested on

macOS 15.4.1 24E263 arm64
Xcode 16.3 16E140

Verification

Have you

• followed our Commit Message Guidelines?
• squashed and minimized your commits?
• checked that there aren't other open pull requests for the same change?
• referenced existing tickets on Trac with full URL in commit message?
• checked your Portfile with port lint?
• tried existing tests with sudo port test?
• tried a full install with sudo port -vst install?
• tested basic functionality of all binary files?
• checked that the Portfile's most important variants haven't been broken?

[macportsbot]

Notifying maintainers:
@barracuda156 for port libayatana-indicator.

[barracuda156]

@thestr4ng3r This was verified with glib2 +x11, right? If yes, then should be good.

[thestr4ng3r]

@thestr4ng3r This was verified with glib2 +x11, right? If yes, then should be good.

@barracuda156 Yes, tested and works fine with glib2 +x11 too.