chore(deps): update nest monorepo

Author: renovate-bot

service/package.json

@@ -28,9 +28,9 @@
     "@blog/markdown": "^6.26.272",
     "@blog/pwa": "^6.26.272",
     "@blog/router": "^6.26.272",
-    "@nestjs/common": "7.6.18",
-    "@nestjs/core": "7.6.18",
-    "@nestjs/platform-express": "7.6.18",
+    "@nestjs/common": "8.4.0",
+    "@nestjs/core": "8.4.0",
+    "@nestjs/platform-express": "8.4.0",
     "@nestjs/serve-static": "2.2.2",
     "class-transformer": "0.4.0",
     "class-validator": "0.13.1",
@@ -46,9 +46,9 @@
     "rxjs": "6.6.7"
   },
   "devDependencies": {
-    "@nestjs/cli": "7.6.0",
+    "@nestjs/cli": "8.2.2",
     "@nestjs/schematics": "8.0.3",
-    "@nestjs/testing": "7.6.18",
+    "@nestjs/testing": "8.4.0",
     "@types/express": "4.17.13",
     "@types/fancy-log": "1.3.1",
     "@types/fs-extra": "9.0.13",