Allow USES=kde without specifying the version

[makc]

Summary

A bunch of ports use only extra cmake modules (ECM), so they do no care about Frameworks version at all. Besides, we have dropped KF5 ECM in favour of KF6 counterpart when we switched to Plasma 6 ports, so both USES=kde:[56] pull the latest ECM.

This patch allows ports to enlist USES=kde without specifying the version.

[arrowd]

LGTM.

[jhale]

With all due respect, I think this is a bad idea. When KF7 rolls around years later and folks have made ports with versionless USES=kde, I can see this becoming a headache. If we are going to support versionless USES=kde, it should only be for specific components like ECM.

Mk/Uses/kde.mk

1055

With the removal of the . else/. endif, all of the indents need to be demoted by 2 spaces.

[arrowd]

Actually, Jason made a good point. How about adding a .warning for cases when USES=kde is versionless and USE_KDE contains anything but ecm?

[makc]

Introduce _USE_KDE_LATEST for components which can be used without requesting KDE Frameworks version.
Convert audio/zrythm to USES=kde.
Drop runtime dependency on ecm for affected ports.

[makc]

In D58578#1344554, @jhale wrote:

With all due respect, I think this is a bad idea. When KF7 rolls around years later and folks have made ports with versionless USES=kde, I can see this becoming a headache. If we are going to support versionless USES=kde, it should only be for specific components like ECM.

Agree.

Mk/Uses/kde.mk

1055

I was going to fix this in a separate commit.

[jhale]

Otherwise, LGTM.

Mk/Uses/kde.mk

79

Small typo: s/specifed/specified

[makc]

Fix spelling and amend indentation.

[adridg]

Mk/Uses/kde.mk

8

"may be omitted when"

[jhale]

Mk/Uses/kde.mk

8

That line sounded weird to me as native English speaker, but I couldn't quite ex[plain why. That is way better wording.