Update min sdks when Combine is used

Author: fl034

modules/openapi-generator/src/main/resources/swift5/Package.swift.mustache

@@ -5,10 +5,18 @@ import PackageDescription
 let package = Package(
     name: "{{projectName}}",
     platforms: [
+        {{#useCombine}}
+        .iOS(.v13),
+        .macOS(.v10_15),
+        .tvOS(.v13),
+        .watchOS(.v6),
+        {{/useCombine}}
+        {{^useCombine}}
         .iOS(.v9),
         .macOS(.v10_11),
         .tvOS(.v9),
         .watchOS(.v3),
+        {{/useCombine}}
     ],
     products: [
         // Products define the executables and libraries produced by a package, and make them visible to other packages.

modules/openapi-generator/src/main/resources/swift5/Podspec.mustache

@@ -1,10 +1,18 @@
 Pod::Spec.new do |s|
   s.name = '{{projectName}}'{{#projectDescription}}
   s.summary = '{{projectDescription}}'{{/projectDescription}}
+  {{#useCombine}}
+  s.ios.deployment_target = '13.0'
+  s.osx.deployment_target = '10.15'
+  s.tvos.deployment_target = '13.0'
+  s.watchos.deployment_target = '6.0'
+  {{/useCombine}}
+  {{^useCombine}}
   s.ios.deployment_target = '9.0'
   s.osx.deployment_target = '10.11'
   s.tvos.deployment_target = '9.0'
   s.watchos.deployment_target = '3.0'
+  {{/useCombine}}
   s.version = '{{#podVersion}}{{podVersion}}{{/podVersion}}{{^podVersion}}{{#apiInfo}}{{version}}{{/apiInfo}}{{^apiInfo}}}0.0.1{{/apiInfo}}{{/podVersion}}'
   s.source = {{#podSource}}{{& podSource}}{{/podSource}}{{^podSource}}{ :git => '[email protected]:OpenAPITools/openapi-generator.git', :tag => 'v{{#apiInfo}}{{version}}{{/apiInfo}}{{^apiInfo}}}0.0.1{{/apiInfo}}' }{{/podSource}}
   {{#podAuthors}}