Revert "[7.17] Bump spotless (elastic#126125) (elastic#126160)" (elastic#126172)

Reverting elastic#126160, which
was a backport of elastic#126125,
due to
elastic#126125 (comment).

Author: joegallo

gradle/build.versions.toml

@@ -38,6 +38,6 @@ shadow-plugin = "com.gradleup.shadow:shadow-gradle-plugin:8.3.5"
 spock-core = { group = "org.spockframework", name="spock-core", version.ref="spock" }
 spock-junit4 = { group = "org.spockframework", name="spock-junit4", version.ref="spock" }
 spock-platform = { group = "org.spockframework", name="spock-bom", version.ref="spock" }
-spotless-plugin = "com.diffplug.spotless:spotless-plugin-gradle:7.0.2"
+spotless-plugin = "com.diffplug.spotless:spotless-plugin-gradle:6.25.0"
 wiremock = "com.github.tomakehurst:wiremock-jre8-standalone:2.23.2"
 xmlunit-core = "org.xmlunit:xmlunit-core:2.8.2"