Require analyzer 6.10.0, stop using deprecated properties of LibraryElement.

[scheglov]

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[srawlins]

Looks like you need to regenerate files with dart tool/task.dart build renderers

[scheglov]

Well, I don't know why PrefixesTest | test_referenced_wildcard fails.
It looks to be related to analyzer 6.10.0 itself, not the LibraryElement related changes.