[swift6][client] make PromiseKit as deprecated

Author: 4brunu

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Swift6ClientCodegen.java

@@ -491,6 +491,9 @@ public void processOpts() {
         additionalProperties.put(RESPONSE_AS, responseAs);
         if (ArrayUtils.contains(responseAs, RESPONSE_LIBRARY_PROMISE_KIT)) {
             additionalProperties.put("usePromiseKit", true);
+            LOGGER.warn("NOTICE: We are considering deprecating PromiseKit support in the Swift 6 generator. " +
+                        "If you are still using it, please share your use case here: " +
+                        "https://github.com/OpenAPITools/openapi-generator/issues/22791");
         }
         if (ArrayUtils.contains(responseAs, RESPONSE_LIBRARY_RX_SWIFT)) {
             additionalProperties.put("useRxSwift", true);

modules/openapi-generator/src/main/resources/swift6/api.mustache

@@ -94,9 +94,7 @@ extension {{projectName}}API {
      - parameter apiConfiguration: The configuration for the http request.{{/apiStaticMethod}}
      - returns: Promise<{{{returnType}}}{{#returnType}}{{#isResponseOptional}}?{{/isResponseOptional}}{{/returnType}}{{^returnType}}Void{{/returnType}}>
      */
-    {{#isDeprecated}}
-    @available(*, deprecated, message: "This operation is deprecated.")
-    {{/isDeprecated}}
+    @available(*, deprecated, message: "{{#isDeprecated}}This operation is deprecated. | {{/isDeprecated}}We are considering deprecating PromiseKit support in the Swift 6 generator. Feedback: https://github.com/OpenAPITools/openapi-generator/issues/22791")
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}open{{/nonPublicApi}} {{#apiStaticMethod}}class {{/apiStaticMethod}}func {{operationId}}({{#allParams}}{{paramName}}: {{#isEnum}}{{#isContainer}}[{{enumName}}_{{operationId}}]{{/isContainer}}{{^isContainer}}{{enumName}}_{{operationId}}{{/isContainer}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}}{{^required}}? = nil{{/required}}{{^-last}}, {{/-last}}{{/allParams}}{{#apiStaticMethod}}{{#hasParams}}, {{/hasParams}}apiConfiguration: {{projectName}}APIConfiguration = {{projectName}}APIConfiguration.shared{{/apiStaticMethod}}) -> Promise<{{{returnType}}}{{#returnType}}{{#isResponseOptional}}?{{/isResponseOptional}}{{/returnType}}{{^returnType}}Void{{/returnType}}> {
         let deferred = Promise<{{{returnType}}}{{#returnType}}{{#isResponseOptional}}?{{/isResponseOptional}}{{/returnType}}{{^returnType}}Void{{/returnType}}>.pending()
         {{operationId}}WithRequestBuilder({{#allParams}}{{paramName}}: {{paramName}}{{^-last}}, {{/-last}}{{/allParams}}{{#apiStaticMethod}}{{#hasParams}}, {{/hasParams}}apiConfiguration: apiConfiguration{{/apiStaticMethod}}).execute { result in