The legacy HTTP package was deprecated in v5 with the launch of
@angular/common/http. The legacy package hasn't been published
since v7, and will therefore not include a migration.
PR Close#27038
If ngcc gets updated to a new version then the artifacts
left in packages that were processed by the previous
version are possibly invalid.
Previously we just errored if we found packages that
had already been processed by an outdated version.
Now we automatically clean the packages that have
outdated artifacts so that they can be reprocessed
correctly with the current ngcc version.
Fixes#35082
PR Close#35079
