Use since attribute in configuration properties deprecation consistently

[snicoll]

Most properties that are deprecated don't have a since attribute. We should revisit them and add the attribute so that new entries have it too. Perhaps we should create a rule to make sure it's added?

[scottfrederick]

I have some changes with an architecture rule that enforces the since attribute on usages of @DeprecatedConfigurationProperty in Boot itself, and adding the attribute to the few places that didn't already have it.

The vast majority of the config property deprecations that don't have since are in additional-spring-configuration-metadata.json files. Do you want to add the attribute on all of those also? It will take some time to research the right version for each of them, but I'm happy to do it if that's what you're thinking.

[snicoll]

Hi Scott! Yes the plan was to add the value in both the code and the manual metadata. I think the manual metadata is the most problematic. I'd recommend checking for the version on the 3.x branch as main is going to show too many unrelated changes.

I'd also research an architecture rule forsrc/main/java/META-INF/spring-configuration-metadata.json and src/main/java/META-INF/additional-spring-configuration-metadata.json first. We have a few modules where we only have manual metadata and we use the first location for those.

Thanks again!