[resttemplate] Removed unnecessary cast to HttpClientErrorException as both classes in the catch extend HttpStatusCodeException

[andeb]

Small clean-up that removes unnecessary cast. Both HttpServerErrorException and HttpClientErrorException extend the base class HttpStatusCodeException and have access to the getStatusCode() method.

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cc @cachescrubber @welshm @MelleD @atextor @manedev79 @javisst @borsch @banlevente @Zomzog @martin-mfg @wing328

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Summary by cubic

Removed an unnecessary cast in the RestTemplate ApiClient retry logic. The code now calls getStatusCode() on the shared base type (HttpStatusCodeException) to detect 429 Too Many Requests, keeping behavior the same while simplifying the condition.

^{Written for commit acc7a69. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 9 files

[wing328]

looks good 👍

let's give it a try

thanks for the contribution