fix(deps): update dependency com.google.cloud:libraries-bom to v26.64.0 (#3963)

* fix(deps): update dependency com.google.cloud:libraries-bom to v26.64.0

* chore: update starter modules in spring-cloud-previews

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Co-authored-by: Mridula <66699525+mpeddada1@users.noreply.github.com>
Co-authored-by: Cloud Java Bot <cloud-java-bot@google.com>

Author: 3 people

spring-cloud-gcp-dependencies/pom.xml

@@ -34,7 +34,7 @@
 	</distributionManagement>
 
 	<properties>
-		<gcp-libraries-bom.version>26.63.0</gcp-libraries-bom.version>
+		<gcp-libraries-bom.version>26.64.0</gcp-libraries-bom.version>
 		<cloud-sql-socket-factory.version>1.25.0</cloud-sql-socket-factory.version>
 		<r2dbc-postgres-driver.version>1.0.7.RELEASE</r2dbc-postgres-driver.version>
 		<cloud-spanner-r2dbc.version>1.3.0</cloud-spanner-r2dbc.version>