remove circleci workflow; convert github workflow into gitea workflow

.circleci/config.yml

@@ -1,13 +0,0 @@
-# Use the latest 2.1 version of CircleCI pipeline process engine. See: https://circleci.com/docs/2.0/configuration-reference
-version: 2.1
-# Use a package of configuration called an orb.
-orbs:
-  # Declare a dependency on the welcome-orb
-  welcome: circleci/welcome-orb@0.4.1
-# Orchestrate or schedule a set of jobs
-workflows:
-  # Name the workflow "welcome"
-  welcome:
-    # Run the welcome/run job in its own container
-    jobs:
-      - welcome/run