ci(github): replace references to master branch with main

.github/workflows/jsonrpc.yml

@@ -2,9 +2,9 @@ name: JSON-RPC API Test
 
 on:
   push:
-    branches: [master]
+    branches: [main]
   pull_request:
-    branches: [master]
+    branches: [main]
 
 env:
   CARGO_TERM_COLOR: always

.github/workflows/node-docs.yml

@@ -8,7 +8,7 @@ name: Generate & upload node.js documentation
 on:
   push:
     branches:
-      - master
+      - main
 
 jobs:
   generate:

.github/workflows/node-tests.yml

@@ -13,7 +13,7 @@ on:
   pull_request:
   push:
     branches:
-      - master
+      - main
 
 jobs:
   tests:

.github/workflows/upload-docs.yml

@@ -3,8 +3,7 @@ name: Build & Deploy Documentation on rs.delta.chat
 on:
   push:
     branches:
-      - master
-      - docs-gh-action
+      - main
 
 jobs:
   build:

.github/workflows/upload-ffi-docs.yml

@@ -7,8 +7,7 @@ name: Build & Deploy Documentation on cffi.delta.chat
 on:
   push:
     branches:
-      - master
-      - docs-gh-action
+      - main
 
 jobs:
   build: