Stop Created-By manifest header from causing a test task cache miss

Previously, when a project's jar was an input into a test task, a
cache hit required the current build to be using the same JDK as the
one that created the cache entry. This was due to the Created-By
entry in the jar's manifest which will vary if JDKs with different
values for the java.version and java.specification.vendor version are
used.

This commit configures normalization of the runtime classpath to ignore
META-INF/MANIFEST.MF, thereby allowing a cache hit when the tests were
previously run on a different JDK than the one being used now. Typically
this is a different update release being used on a CI agent and a
developer's machine. This change will therefore improve the likelihood
of a cache hit once remote caching has been enabled.

Closes gh-23872

gradle/spring-module.gradle

@@ -18,6 +18,12 @@ jar {
 	}
 }
 
+normalization {
+	runtimeClasspath {
+		ignore "META-INF/MANIFEST.MF"
+	}
+}
+
 javadoc {
 	description = "Generates project-level javadoc for use in -javadoc jar"
 

integration-tests/integration-tests.gradle

@@ -20,3 +20,9 @@ dependencies {
 	testCompile("org.hsqldb:hsqldb")
 	testCompile("org.hibernate:hibernate-core")
 }
+
+normalization {
+	runtimeClasspath {
+		ignore "META-INF/MANIFEST.MF"
+	}
+}