Add inference YAML tests to rest-resources-zip (elastic#130070) (elastic#130105)

(cherry picked from commit 21180df)

Author: pquentin

x-pack/plugin/inference/build.gradle

@@ -406,3 +406,7 @@ tasks.named("thirdPartyAudit").configure {
 tasks.named('yamlRestTest') {
   usesDefaultDistribution("Uses the inference API")
 }
+
+artifacts {
+  restXpackTests(new File(projectDir, "src/yamlRestTest/resources/rest-api-spec/test"))
+}

x-pack/rest-resources-zip/build.gradle

@@ -27,6 +27,7 @@ dependencies {
   platinumTests project(path: ':x-pack:plugin', configuration: 'restXpackTests')
   platinumTests project(path: ':x-pack:plugin:eql:qa:rest', configuration: 'restXpackTests')
   platinumTests project(path: ':x-pack:plugin:ent-search', configuration: 'restXpackTests')
+  platinumTests project(path: ':x-pack:plugin:inference', configuration: 'restXpackTests')
   platinumCompatTests project(path: ':x-pack:plugin', configuration: 'restCompatTests')
   platinumCompatTests project(path: ':x-pack:plugin:eql:qa:rest', configuration: 'restCompatTests')
 }