Remove compiler warnings for spring-security-rsocket

[JiHunparkkk]

Closes gh-18437

Changes

• Apply plugin compile-warnings-error
• Add jsr305 as compileOnly dependency to resolve unknown enum constant When.MAYBE warning caused by reactor-core/rsocket-core dependencies

Before

After

Remaining Deprecation Note

AuthenticationPayloadInterceptor uses deprecated BasicAuthenticationPayloadExchangeConverter as default value.

Changing the default to AuthenticationPayloadExchangeConverter would resolve this warning, but it may introduce a breaking change since the two converters use different authentication protocols:

• BasicAuthenticationPayloadExchangeConverter: BASIC_AUTHENTICATION_MIME_TYPE
• AuthenticationPayloadExchangeConverter: RSocket Authentication Extension

Please advise if this change should be included.

Test plan

• ./gradlew --no-build-cache clean :spring-security-rsocket:check