SpringBoot Remove duplicate declaration of jackson-databind

Removes duplicate declaration of com.fasterxml.jackson.core:jackson-databind from buildSrc/build.gradle file.

Related to #25177

Comment From: wilkinsona

Whoops. Thanks for spotting this, @rand0m86.

Comment From: wilkinsona

Thanks very much for making your first contribution to Spring Boot, @rand0m86.