chore!: use new class keywords for credentials

Author: JKRhb

lib/src/core/credentials/ace_credentials.dart

@@ -10,7 +10,7 @@ import '../../definitions/security/ace_security_scheme.dart';
 import 'credentials.dart';
 
 /// [Credentials] used for the [AceSecurityScheme].
-class AceCredentials extends Credentials {
+final class AceCredentials extends Credentials {
   /// Constructor.
   AceCredentials(this.accessToken);
 

lib/src/core/credentials/apikey_credentials.dart

@@ -9,7 +9,7 @@ import '../../definitions/security/apikey_security_scheme.dart';
 import 'credentials.dart';
 
 /// [Credentials] used for the [ApiKeySecurityScheme].
-class ApiKeyCredentials extends Credentials {
+final class ApiKeyCredentials extends Credentials {
   /// Constructor.
   ApiKeyCredentials(this.apiKey);
 

lib/src/core/credentials/basic_credentials.dart

@@ -11,7 +11,7 @@ import 'credentials.dart';
 /// [Credentials] used for the [BasicSecurityScheme].
 ///
 /// Provides an unencrypted [username] and [password] combination.
-class BasicCredentials extends Credentials {
+final class BasicCredentials extends Credentials {
   /// Constructor.
   BasicCredentials(this.username, this.password);
 

lib/src/core/credentials/bearer_credentials.dart

@@ -9,7 +9,7 @@ import '../../definitions/security/bearer_security_scheme.dart';
 import 'credentials.dart';
 
 /// [Credentials] used for the [BearerSecurityScheme].
-class BearerCredentials extends Credentials {
+final class BearerCredentials extends Credentials {
   /// Constructor.
   BearerCredentials(this.token);
 

lib/src/core/credentials/credentials.dart

@@ -5,4 +5,4 @@
 // SPDX-License-Identifier: BSD-3-Clause
 
 /// Base class used for defining credentials for Thing Interactions.
-abstract class Credentials {}
+base class Credentials {}

lib/src/core/credentials/digest_credentials.dart

@@ -8,7 +8,7 @@ import '../../definitions/security/digest_security_scheme.dart';
 import 'credentials.dart';
 
 /// [Credentials] used for the [DigestSecurityScheme].
-class DigestCredentials extends Credentials {
+final class DigestCredentials extends Credentials {
   /// Constructor.
   DigestCredentials(this.username, this.password);
 

lib/src/core/credentials/oauth2_credentials.dart

@@ -8,7 +8,7 @@ import '../../definitions/security/oauth2_security_scheme.dart';
 import 'credentials.dart';
 
 /// [Credentials] used for the [OAuth2SecurityScheme].
-class OAuth2Credentials extends Credentials {
+final class OAuth2Credentials extends Credentials {
   /// Constructor.
   OAuth2Credentials([this.secret]);
 

lib/src/core/credentials/psk_credentials.dart

@@ -10,7 +10,7 @@ import '../../definitions/security/psk_security_scheme.dart';
 import 'credentials.dart';
 
 /// [Credentials] used for the [PskSecurityScheme].
-class PskCredentials extends Credentials {
+final class PskCredentials extends Credentials {
   /// Constructor.
   PskCredentials({required this.preSharedKey, required this.identity});