Consistently document the minimum supported versions of Gradle

Closes gh-43725

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/antora/modules/gradle-plugin/pages/index.adoc

@@ -3,6 +3,6 @@
 
 The Spring Boot Gradle Plugin provides Spring Boot support in https://gradle.org[Gradle].
 It allows you to package executable jar or war archives, run Spring Boot applications, and use the dependency management provided by `spring-boot-dependencies`.
-Spring Boot's Gradle plugin requires Gradle 7.x (7.5 or later) or 8.x and can be used with Gradle's {url-gradle-docs}/configuration_cache.html[configuration cache].
+Spring Boot's Gradle plugin requires Gradle 7.x (7.6.4 or later) or 8.x (8.4 or later) and can be used with Gradle's {url-gradle-docs}/configuration_cache.html[configuration cache].
 
 In addition to this user guide, xref:api/java/index.html[API documentation] is also available.