test for build-missing of transitive tool-requires

[memsharded]

Changelog: Bugfix: --build=missing was doing unnecessary builds of packages that were not needed and could be skipped, in the case of tool_requires having transitive dependencies.
Docs: Omit

[AbrilRBS]

🤯
After playing around with this seems like pure bad luck that we didn't catch it earlier

[memsharded]

After playing around with this seems like pure bad luck that we didn't catch it earlier

The main reason could be that it doesn't really fail, but it builds from source, so unless it is something slow and you are paying attention, it can go unnoticed. And of course, also that the scenario is not that common:

• tool_requires with transitive dependencies
• Doing a --build=missing
• Actually missing those transitive dependencies binaries, which is very unlikely (I realized because I copied to a private repo and remove conancenter remote)