fix: update to ubuntu-latest, github doesnt support 1804

Author: FreaKzero

.github/workflows/develop.yml

@@ -8,7 +8,7 @@ jobs:
   build:
     timeout-minutes: 20
     name: Check
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v1
 

.github/workflows/prtitle.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   main:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     steps:
       - uses: amannn/action-semantic-pull-request@v1.1.1
         env: