spec(deps): use node 20 (MisskeyIO#197)

.github/workflows/test-backend.yml

@@ -13,7 +13,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [18.x]
+        node-version: [20.x]
 
     services:
       postgres:

.github/workflows/test-frontend.yml

@@ -13,7 +13,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [18.x]
+        node-version: [20.x]
 
     steps:
     - uses: actions/checkout@v3.3.0
@@ -51,7 +51,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: [18.x]
+        node-version: [20.x]
         browser: [chrome]
 
     services:

.github/workflows/test-misskey-js.yml

@@ -16,7 +16,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [18.x]
+        node-version: [20.x]
         # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
 
     steps:

.github/workflows/test-production.yml

@@ -16,7 +16,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [18.x]
+        node-version: [20.x]
 
     steps:
     - uses: actions/checkout@v3.3.0