deps: update dependency com.google.errorprone:error_prone_annotations to v2.8.1 (#588)
deps: update dependency com.google.errorprone:error_prone_annotations to v2.8.1 (#588)

[![WhiteSource Renovate](https://app.renovatebot.com/images/banner.svg)](https://renovatebot.com)

This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [com.google.errorprone:error_prone_annotations](https://errorprone.info) ([source](https://togithub.com/google/error-prone)) | `2.7.1` -> `2.8.1` | [![age](https://badges.renovateapi.com/packages/maven/com.google.errorprone:error_prone_annotations/2.8.1/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/maven/com.google.errorprone:error_prone_annotations/2.8.1/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/maven/com.google.errorprone:error_prone_annotations/2.8.1/compatibility-slim/2.7.1)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/maven/com.google.errorprone:error_prone_annotations/2.8.1/confidence-slim/2.7.1)](https://docs.renovatebot.com/merge-confidence/) |

---

### Release Notes

<details>
<summary>google/error-prone</summary>

### [`v2.8.1`](https://togithub.com/google/error-prone/compare/v2.8.0...v2.8.1)

[Compare Source](https://togithub.com/google/error-prone/compare/v2.8.0...v2.8.1)

### [`v2.8.0`](https://togithub.com/google/error-prone/releases/v2.8.0)

[Compare Source](https://togithub.com/google/error-prone/compare/v2.7.1...v2.8.0)

New Checks:

-   [JUnit4TestsNotRunWithinEnclosed](https://errorprone.info/bugpattern/JUnit4TestsNotRunWithinEnclosed)
-   [OptionalOfRedundantMethod](https://errorprone.info/bugpattern/OptionalOfRedundantMethod)
-   [UnnecessaryAssignment](https://errorprone.info/bugpattern/UnnecessaryAssignment)
-   [UnrecognisedJavadocTag](https://errorprone.info/bugpattern/UnrecognisedJavadocTag)
-   [AnnotationMirrorToString](https://errorprone.info/bugpattern/AnnotationMirrorToString)
-   [AnnotationValueToString](https://errorprone.info/bugpattern/AnnotationValueToString)
-   [EqualsMissingNullable](https://errorprone.info/bugpattern/EqualsMissingNullable)
-   [ReturnMissingNullable](https://errorprone.info/bugpattern/ReturnMissingNullable)

Fixes [#&#8203;1652](https://togithub.com/google/error-prone/issues/1652), [#&#8203;2122](https://togithub.com/google/error-prone/issues/2122), [#&#8203;2122](https://togithub.com/google/error-prone/issues/2122), [#&#8203;2366](https://togithub.com/google/error-prone/issues/2366), [#&#8203;2404](https://togithub.com/google/error-prone/issues/2404), [#&#8203;2411](https://togithub.com/google/error-prone/issues/2411)

</details>

---

### Configuration

📅 **Schedule**: At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update again.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box.

---

This PR has been generated by [WhiteSource Renovate](https://renovate.whitesourcesoftware.com). View repository job log [here](https://app.renovatebot.com/dashboard#github/googleapis/java-speech).
googleapis/google-cloud-java,googleapis/google-cloud-java,googleapis/google-cloud-java