SpringBoot Automatically align buildSrc's Framework version with the version used in the main build

Our Gradle buildSrc folder has a dependency on Spring 5. We should ideally align versions across the codebase.

Comment From: wilkinsona

We already do so with the version of Kotlin. Hopefully we can use the same mechanism for the Framework version as well.

Comment From: wilkinsona

When we move to Framework snapshots, I wonder what impact this will have on the build in terms of cache misses. I think it would mean that our plugins all change whenever a new Framework snapshot's published which I think will cause cache misses. This could make the build take longer. I guess we should try it and see how big an impact it has and refine from there as needed.