use inbuilt injected logger

src/index.ts

 import 'source-map-support/register';
-import { Context } from 'koishi';
+import { Context, Logger } from 'koishi';
 import {
   PicSourceLoliconPluginConfig,
   PicSourceLoliconPluginConfigLike,
@@ -10,6 +10,7 @@ import {
   DefinePlugin,
   Inject,
   InjectConfig,
+  InjectLogger,
   LifecycleEvents,
 } from 'koishi-thirdeye';
 
@@ -31,6 +32,9 @@ export default class PicSourceLolicon
   @Inject(true)
   private pics: PicsContainer;
 
+  @InjectLogger()
+  private logger: Logger;
+
   onApply() {
     this.config.applyTo(this);
     this.pics.addSource(this);
@@ -50,13 +54,11 @@ export default class PicSourceLolicon
       },
     );
     if (result.error) {
-      this.ctx
-        .logger('picsource-lolicon')
-        .warn(
-          `Failed to get Lolicon random pic ${picTags.join(',')}: ${
-            result.error
-          }`,
-        );
+      this.logger.warn(
+        `Failed to get Lolicon random pic ${picTags.join(',')}: ${
+          result.error
+        }`,
+      );
       return;
     }
     if (!result.data?.length) {