fix: remove unnessacary things from extension for initial version

src/main/groovy/com/fahrecker/gradle/FlutterExtension.groovy

@@ -1,25 +1,4 @@
 package com.fahrecker.gradle
 
 class FlutterExtension {
-    final Property<String> flutterVersion
-    final Property<String> flutterChannel
-    final Property<String> flutterSdkPath
-
-    FlutterExtension(Project project) {
-        flutterVersion = project.objects.property(String)
-        flutterChannel = project.objects.property(String)
-        flutterSdkPath = project.objects.property(String)
-    }
-
-    void setFlutterVersion(String version) {
-        flutterVersion.set(version)
-    }
-
-    void setFlutterChannel(String channel) {
-        flutterChannel.set(channel)
-    }
-
-    void setFlutterSdkPath(String path) {
-        flutterSdkPath.set(path)
-    }
 }

src/main/groovy/com/fahrecker/gradle/FlutterGradlePlugin.groovy

@@ -2,7 +2,6 @@ package com.fahrecker.gradle
 
 import org.gradle.api.Plugin
 import org.gradle.api.Project
-import org.gradle.api.provider.Property
 
 class FlutterGradlePlugin implements Plugin<Project> {
     void apply(Project project) {