As of now, when the google auth library provides a new method for GAX, we need to release Google Cloud BOM and the Libraries BOM that contains the newer version of the google auth library. Until that, GAX cannot use the google auth library because Linkage Monitor complains:

googleapis/gax-java#1420 (comment)

Once the Libraries BOM release is done, we can upgrade the google auth library version in GAX.

Is there a better way?

CC: @Neenu1995