build: Use spring-web instead of spring-webflux in spring-ai-retry

[pkubowicz]

The dependency on spring-webflux was unnecessary, there was no code inside spring-ai-retry that made use of it.

Also remove 'optional' from slf4j-api dependency (it's not optional, if you don't have it on classpath, RetryUtils will fail to load).

Fixes #3307

[markpollack]

Thanks, great catch.

[ilayaperumalg]

@pkubowicz Thanks for the PR! As you can see from the compilation issues with the build, the dependency web-flux is being used by a few other modules via spring-ai-retry. It appears that we need a better strategy in terms of defining common vs specific dependencies for the individual modules.

[pkubowicz]

I don't think 'retry' module should be the place to decide on common dependencies. Especially, the decision on the web client library used should not be in a helper/tooling module like 'retry'.

Being explicit about dependencies is a well-known rule to build reusable publicly available libraries. Is it worth a discussion? To me, the fix is straightforward, and is to make the dependency on webflux explicit in each place using it. I was surprised the rule is not consequently applied to this repository, hence the compilation failure. But the fix should be easy, and if you don't have anything against, I will add it to my PR.

[ilayaperumalg]

I don't think 'retry' module should be the place to decide on common dependencies. Especially, the decision on the web client library used should not be in a helper/tooling module like 'retry'.

I agree as that's exactly what you fixed in this.

Being explicit about dependencies is a well-known rule to build reusable publicly available libraries. Is it worth a discussion?
I marked this to "to discuss" for the team to identify any other similar dependencies and potentially move these common dependencies to their respective common/shared module.

Feel free to update the PR with your suggestion.

[pkubowicz]

I rebased on the current main and added the explicit dependency on spring-webflux where compilation failed without it.

[ilayaperumalg]

Rebased and merged as cecc046