improve check for multi-variant dependencies per generation of easyconfigs (for now, only for 2025a & newer)

[boegel]

Issues fixed:

• also check dependency variants for easyconfigs using a GCC toolchain;
• also check dependency variants for easyconfigs using a GCCcore-10.* toolchain;
• check dependency variants per generation of easyconfigs (fixes make check for dependency versions per toolchain generation aware of subtoolchains #9846);

[boegel]

Once the tests pass, I should probably pull out the Hadoop change into its own PR, to highlight the change (so it'll be listed in the release notes)...

edit: see #12709

[boegel]

I need to verify that this indeed picks up on different dependency variants across (sub)toolchains in the same generation, so don't merge this just yet...

[Flamefire]

Just remembered this old PR as we recently had the case that there is a Java 17 and Java 21 in our toolchain as some easyconfigs were GCC(core) and others foss so the conflict was missed.
Just as a motivation to finish this ;-)

[akesandgren]

Yeah, ping @boegel

[branfosj]

Suggested change

	from easybuild.tools.build_log import EasyBuildError, print_warning
	from easybuild.tools.build_log import EasyBuildError

[boegel]

@branfosj Let's throw that info in dedicated issues (per toolchain generation), so we can follow up?

[branfosj]

@branfosj Let's throw that info in dedicated issues (per toolchain generation), so we can follow up?

I've moved the comment into #23133 and #23134

[jfgrimm]

Going in, thanks @boegel!