Remove remaining native build-time class initializations

See oracle/graal#4673 related issue.

Closes gh-29018

Author: sdeleuze

spring-core/src/main/resources/META-INF/native-image/org.springframework/spring-core/native-image.properties

@@ -1,8 +1,4 @@
-Args = --initialize-at-build-time=org.springframework.aot.graalvm.ThrowawayClassLoader,\
-org.springframework.util.ClassUtils,\
-org.springframework.util.ConcurrentReferenceHashMap,\
-org.springframework.util.MimeType,\
-org.springframework.util.MimeTypeUtils \
+Args = --initialize-at-build-time=org.springframework.aot.graalvm.ThrowawayClassLoader \
 --add-exports org.graalvm.nativeimage.builder/com.oracle.svm.hosted=ALL-UNNAMED \
 --add-exports jdk.internal.vm.compiler/org.graalvm.compiler.debug=ALL-UNNAMED \
 --add-exports jdk.internal.vm.ci/jdk.vm.ci.meta=ALL-UNNAMED \