cmake: Allow WITH_DBUS on all Unix-like systems

[hebasto]

This PR makes the WITH_DBUS option available on all Unix-like systems, not just Linux, thereby fixing a regression that was overlooked during the migration from Autotools.

Note: Enabling D-Bus support on macOS still makes no sense, since the Notificator class uses the User Notification Center regardless:

bitcoin/src/qt/notificator.cpp

Lines 43 to 56 in 746ab19

	#ifdef USE_DBUS
	interface = new QDBusInterface("org.freedesktop.Notifications",
	"/org/freedesktop/Notifications", "org.freedesktop.Notifications");
	if(interface->isValid())
	{
	mode = Freedesktop;
	}
	#endif
	#ifdef Q_OS_MACOS
	// check if users OS has support for NSUserNotification
	if( MacNotificationHandler::instance()->hasUserNotificationCenterSupport()) {
	mode = UserNotificationCenter;
	}
	#endif

Fixes #32464.

[DrahtBot]

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Code Coverage & Benchmarks

For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/32469.

Reviews

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Type	Reviewers
ACK	laanwj, theStack

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[laanwj]

ACK 5b7ed46

This is conceptually correct because freedesktop DBUS is a standard for UNIX-like systems, not specifically Linux.

[theStack]

tACK 5b7ed46

Tested with OpenBSD 7.7, xfce4.20.0 and the dbus-1.16.2p0v0 package installed that configuring the build with -DBUILD_GUI=ON enables "DBus (GUI)" and that DBus is indeed used for notifications (added a debug message at the proper place just to be sure).

[fanquake]

Backported to 29.x in #32292.

[DrahtBot]

Guix builds (on x86_64) [untrusted test-only build, possibly unsafe, not for production use]

File	commit 59e09e0 (master)	commit c8b7be9644049b4ab7d6aba40c072d69e8d22d1c (pull/32469/merge)
*-aarch64-linux-gnu-debug.tar.gz	68b4709ba4fcd0fb...	b492c110e09612f5...
*-aarch64-linux-gnu.tar.gz	d8a7019b5d541037...	fe3308d65713934f...
*-arm-linux-gnueabihf-debug.tar.gz	399b1805e91cf2d2...	6a540d1de0bd1e04...
*-arm-linux-gnueabihf.tar.gz	ea6460f0bfe87d1c...	b2cf30520d1a67f0...
*-arm64-apple-darwin-codesigning.tar.gz	27255afe7335202a...	1e34019f4780f51c...
*-arm64-apple-darwin-unsigned.tar.gz	a3aff4ec7d2eec4a...	6fc67351008e560e...
*-arm64-apple-darwin-unsigned.zip	c3ce63185771bfce...	3f573bb936821755...
*-powerpc64-linux-gnu-debug.tar.gz	2c115b5b384c99df...	14644d8a7e9613c0...
*-powerpc64-linux-gnu.tar.gz	859aaa8402ad339b...	628ab195ef789fe1...
*-riscv64-linux-gnu-debug.tar.gz	ce89fc7d14361a68...	2abee328b66746a9...
*-riscv64-linux-gnu.tar.gz	655dd23b243c00a8...	6b213b6cfd701d07...
*-x86_64-apple-darwin-codesigning.tar.gz	29c149cdc7651356...	a4747f032efff371...
*-x86_64-apple-darwin-unsigned.tar.gz	dada9e3cf6d13a2e...	351b306c69489bfe...
*-x86_64-apple-darwin-unsigned.zip	9fbe3961e79a34e6...	703a2265a2701560...
*-x86_64-linux-gnu-debug.tar.gz	279dbd688201b4d2...	4147379aa9a07543...
*-x86_64-linux-gnu.tar.gz	d5a3f239389ebc9e...	6947a40506b7e5b7...
*.tar.gz	3b6128e9e89723e8...	3ac29d16ec9b7f49...
SHA256SUMS.part	3fce865fa49d5e5d...	07b56bda4ede001c...
guix_build.log	78c53171c0047872...	0a381667c4011846...
guix_build.log.diff		60c179c8a3d291c1...