Remove 'experimental' variant from dependency resolution tests With the 'GRADLE_METADATA' feature preview gone, we now only have two dimensions of variation to test:
(1) Ivy or Maven repository? (2) Gradle metadata available - in addition to pom or ivy - or not?
If Gradle 6+ was used for publishing, Gradle metadata is most likely available and the pom/ivy file contains the corresponding marker. If an older Gradle version (or Maven/Ivy) was used for publishing, Gradle metadata is not available and there is also no marker in the other metadata file.