chore: release 3.15.4 (#535)
chore: release 3.15.4 (#535)

:robot: I have created a release \*beep\* \*boop\*
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### [3.15.4](https://www.github.com/googleapis/nodejs-asset/compare/v3.15.3...v3.15.4) (2021-08-11)


### Bug Fixes

* **build:** migrate to using main branch ([#534](https://www.github.com/googleapis/nodejs-asset/issues/534)) ([30fa2c4](https://www.github.com/googleapis/nodejs-asset/commit/30fa2c48abe3de2a9482ea5bde9a4f315a726b89))
---


This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please).
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