Bump cloud.google.com/go/speech from 1.20.1 to 1.21.0

Bumps [cloud.google.com/go/speech](https://github.com/googleapis/google-cloud-go) from 1.20.1 to 1.21.0.
- [Release notes](https://github.com/googleapis/google-cloud-go/releases)
- [Changelog](https://github.com/googleapis/google-cloud-go/blob/main/documentai/CHANGES.md)
- [Commits](googleapis/google-cloud-go@video/v1.20.1...pubsub/v1.21.0)

---
updated-dependencies:
- dependency-name: cloud.google.com/go/speech
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

go.mod

@@ -3,7 +3,7 @@ module github.com/complexorganizations/speech-synthesis
 go 1.16
 
 require (
-	cloud.google.com/go/speech v1.20.1
+	cloud.google.com/go/speech v1.21.0
 	cloud.google.com/go/texttospeech v1.7.4
 	google.golang.org/genproto v0.0.0-20231016165738-49dd2c1f3d0b
 )

go.sum

@@ -804,8 +804,8 @@ cloud.google.com/go/speech v1.15.0/go.mod h1:y6oH7GhqCaZANH7+Oe0BhgIogsNInLlz542
 cloud.google.com/go/speech v1.17.1/go.mod h1:8rVNzU43tQvxDaGvqOhpDqgkJTFowBpDvCJ14kGlJYo=
 cloud.google.com/go/speech v1.19.0/go.mod h1:8rVNzU43tQvxDaGvqOhpDqgkJTFowBpDvCJ14kGlJYo=
 cloud.google.com/go/speech v1.19.1/go.mod h1:WcuaWz/3hOlzPFOVo9DUsblMIHwxP589y6ZMtaG+iAA=
-cloud.google.com/go/speech v1.20.1 h1:OpJ666ao7XxXewGSAkDUJnW188tJ5hNPoM7pZB+Q730=
-cloud.google.com/go/speech v1.20.1/go.mod h1:wwolycgONvfz2EDU8rKuHRW3+wc9ILPsAWoikBEWavY=
+cloud.google.com/go/speech v1.21.0 h1:qkxNao58oF8ghAHE1Eghen7XepawYEN5zuZXYWaUTA4=
+cloud.google.com/go/speech v1.21.0/go.mod h1:wwolycgONvfz2EDU8rKuHRW3+wc9ILPsAWoikBEWavY=
 cloud.google.com/go/storage v1.0.0/go.mod h1:IhtSnM/ZTZV8YYJWCY8RULGVqBDmpoyjwiyrjsg+URw=
 cloud.google.com/go/storage v1.5.0/go.mod h1:tpKbwo567HUNpVclU5sGELwQWBDZ8gh0ZeosJ0Rtdos=
 cloud.google.com/go/storage v1.6.0/go.mod h1:N7U0C8pVQ/+NIKOBQyamJIeKQKkZ+mxpohlUTyfDhBk=