Fix stable warnings

Author: mustard-mh

components/ide/jetbrains/gateway-plugin/build.gradle.kts

@@ -3,9 +3,9 @@
 // See License.AGPL.txt in the project root for license information.
 
 import io.gitlab.arturbosch.detekt.Detekt
-import org.jetbrains.changelog.Changelog
 import org.jetbrains.changelog.markdownToHTML
 import org.jetbrains.intellij.platform.gradle.IntelliJPlatformType
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 fun properties(key: String) = project.findProperty(key).toString()
@@ -146,7 +146,9 @@ tasks.withType<Detekt> {
 }
 
 tasks.withType<KotlinCompile> {
-    kotlinOptions.jvmTarget = "21"
+    compilerOptions {
+        jvmTarget.set(JvmTarget.JVM_21)
+    }
 }
 
 tasks.withType<JavaCompile> {

components/ide/jetbrains/gateway-plugin/src/main/kotlin/io/gitpod/jetbrains/auth/GitpodAuthCallbackHandler.kt

@@ -25,7 +25,7 @@ internal class GitpodAuthCallbackHandler : RestService() {
         request: FullHttpRequest,
         context: ChannelHandlerContext
     ): String? {
-        service.handleServerCallback(urlDecoder.path(), urlDecoder.parameters())
+        service.handleOAuthServerCallback(urlDecoder.path(), urlDecoder.parameters())
         sendResponse(
             request,
             context,

components/ide/jetbrains/gateway-plugin/src/main/kotlin/io/gitpod/jetbrains/auth/GitpodAuthService.kt

@@ -19,7 +19,6 @@ import com.intellij.ide.passwordSafe.PasswordSafe
 import com.intellij.openapi.Disposable
 import com.intellij.openapi.components.Service
 import com.intellij.openapi.components.service
-import com.intellij.util.Base64
 import com.intellij.util.EventDispatcher
 import com.intellij.util.Url
 import com.intellij.util.Urls.encodeParameters
@@ -138,7 +137,7 @@ internal class GitpodAuthService : OAuthServiceBase<Credentials>() {
 
                 val jwt = with(jacksonMapper) {
                     propertyNamingStrategy = PropertyNamingStrategies.LowerCaseStrategy()
-                    readValue(Base64.decode(responseData.accessToken.split('.')[1]), JsonWebToken::class.java)
+                    readValue(Base64.getDecoder().decode(responseData.accessToken.split('.')[1]), JsonWebToken::class.java)
                 }
                 SimpleCredentials(jwt.jti)
             }
@@ -178,7 +177,7 @@ internal class GitpodAuthService : OAuthServiceBase<Credentials>() {
 
         suspend fun authorize(gitpodHost: String): String {
             val accessToken = instance.authorize(gitpodHost).await().accessToken
-            setAccessToken(gitpodHost, accessToken!!)
+            setAccessToken(gitpodHost, accessToken)
             return accessToken
         }