chore(deps): update dependency com.google.cloud:google-cloud-datastore to v2.26.4 (googleapis#1777)

This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [com.google.cloud:google-cloud-datastore](https://redirect.github.com/googleapis/java-datastore) | `2.26.3` -> `2.26.4` | [![age](https://developer.mend.io/api/mc/badges/age/maven/com.google.cloud:google-cloud-datastore/2.26.4?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://developer.mend.io/api/mc/badges/adoption/maven/com.google.cloud:google-cloud-datastore/2.26.4?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://developer.mend.io/api/mc/badges/compatibility/maven/com.google.cloud:google-cloud-datastore/2.26.3/2.26.4?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://developer.mend.io/api/mc/badges/confidence/maven/com.google.cloud:google-cloud-datastore/2.26.3/2.26.4?slim=true)](https://docs.renovatebot.com/merge-confidence/) |

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### Release Notes

<details>
<summary>googleapis/java-datastore (com.google.cloud:google-cloud-datastore)</summary>

### [`v2.26.4`](https://redirect.github.com/googleapis/java-datastore/blob/HEAD/CHANGELOG.md#2264-2025-02-26)

[Compare Source](https://redirect.github.com/googleapis/java-datastore/compare/v2.26.3...v2.26.4)

##### Dependencies

-   Update dependency com.google.cloud:sdk-platform-java-config to v3.44.0 ([#&#8203;1769](https://redirect.github.com/googleapis/java-datastore/issues/1769)) ([7a86509](https://redirect.github.com/googleapis/java-datastore/commit/7a8650939e652fc3b384053454d6ef5084bb1508))

</details>

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Author: renovate-bot

samples/install-without-bom/pom.xml

@@ -29,7 +29,7 @@
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>google-cloud-datastore</artifactId>
-      <version>2.26.3</version>
+      <version>2.26.4</version>
     </dependency>
     <!-- [END datastore_install_without_bom] -->