chore: release 2.1.0 (googleapis#54)

* updated CHANGELOG.md [ci skip]

* updated setup.cfg [ci skip]

* updated setup.py

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

chore: release 2.0.0 (googleapis#35)

* updated CHANGELOG.md [ci skip]

* updated setup.cfg [ci skip]

* updated setup.py

* Update CHANGELOG.md

* Update CHANGELOG.md

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>
Co-authored-by: Bu Sun Kim <8822365+busunkim96@users.noreply.github.com>

chore: release 1.0.1 (googleapis#14)

chore: release 1.0.0 (googleapis#10)

Release 0.5.0 (#8771)

Release 0.4.0 (#7302)

Release texttospeech 0.3.0 (#6997)

* Release 0.3.0

Release texttospeech 0.2.0 (#5475)

Release 0.1.0 (#5062)