Switch to Jakarta servlet, remove Java 8 support

aws/src/main/kotlin/ws/osiris/aws/Config.kt

@@ -89,11 +89,11 @@ data class ApplicationConfig(
     /**
      * The runtime that should be used for the Osiris lambda function.
      *
-     * This should normally be left as the default ([LambdaRuntime.Java8]).
+     * This should normally be left as the default ([LambdaRuntime.Java11]).
      *
      * If you specify a layer that provides an alternative runtime then use [LambdaRuntime.Provided].
      */
-    val runtime: LambdaRuntime = LambdaRuntime.Java8
+    val runtime: LambdaRuntime = LambdaRuntime.Java11
 ) {
     init {
         check(stages.isNotEmpty()) { "There must be at least one stage defined in the configuration" }
@@ -224,12 +224,15 @@ interface ApiFactory<T : ComponentsProvider> {
  */
 enum class LambdaRuntime(val runtimeName: String) {
 
-    /** The AWS Java 8 lambda runtime. */
-    Java8("java8"),
-
     /** The AWS Java 11 lambda runtime. */
     Java11("java11"),
 
+    /** The AWS Java 17 lambda runtime. */
+    Java17("java17"),
+
+    /** The AWS Java 21 lambda runtime. */
+    Java21("java21"),
+
     /** A custom runtime provided by one of the [layers][ApplicationConfig.layers] */
     Provided("provided");
 }

local-server/src/main/kotlin/ws/osiris/localserver/LocalServer.kt

@@ -24,10 +24,10 @@ import java.io.BufferedReader
 import java.io.InputStreamReader
 import java.nio.file.Paths
 import java.util.stream.Collectors.joining
-import javax.servlet.ServletConfig
-import javax.servlet.http.HttpServlet
-import javax.servlet.http.HttpServletRequest
-import javax.servlet.http.HttpServletResponse
+import jakarta.servlet.ServletConfig
+import jakarta.servlet.http.HttpServlet
+import jakarta.servlet.http.HttpServletRequest
+import jakarta.servlet.http.HttpServletResponse
 
 private val log = LoggerFactory.getLogger("ws.osiris.localserver")
 
@@ -116,7 +116,7 @@ private fun HttpServletResponse.write(httpStatus: Int, headers: Headers, body: A
  * runs and joins the server, so the method never returns and the server can only be stopped by killing
  * the process.
  *
- * The `contextRoot` argument controls the URL on which the API is available. By default the API is
+ * The `contextRoot` argument controls the URL on which the API is available. By default, the API is
  * available at:
  *
  *     http://localhost:8080/