Disable macOS 11 pipeline except PR to master

macOS 11 building process takes about 30 minutes vs 18 on macOS 12. And in the same way there's low possibility that what builds on macOS 12 wouldn't build on macOS 11.

Author: yaroslavyaroslav

.github/workflows/linux.yml

@@ -1,25 +1,12 @@
 name: "macOS 11"
 
 on:
-  push:
-    branches:
-      - master
-      - develop
-      - hotfix
-      - feature/github-actions-2.0
-    paths:
-      - Packag*.swift
-      - web3swift.podspec
-      - Cartfile
-      - Sources/**
-      - 'Tests/**'
-      - 'web3swift*/**'
-      - '.github/workflows/**'
   pull_request:
     branches:
       - master
-      - develop
-      - unstable
+
+env:
+  DEVELOPER_DIR: /Applications/Xcode_13.2.1.app/Contents/Developer
 
 jobs:
   spm:
@@ -28,8 +15,6 @@ jobs:
     concurrency: 
       group: spm-${{ github.run_id }}
       cancel-in-progress: false
-    env:
-      DEVELOPER_DIR: /Applications/Xcode_13.2.1.app/Contents/Developer
     steps:
       - uses: actions/checkout@v2
       - name: Resolve dependencies
@@ -46,14 +31,13 @@ jobs:
         run: swift test --skip-build -c debug --filter localTests
       - name: Run remote tests
         run: swift test --skip-build -c debug --filter remoteTests
+
   carthage-iOS:
     name: Carthage
     runs-on: macOS-11
     concurrency: 
       group: carthage-${{ github.run_id }}
       cancel-in-progress: false
-    env:
-      DEVELOPER_DIR: /Applications/Xcode_13.2.1.app/Contents/Developer
     strategy:
       fail-fast: false
       max-parallel: 2

.github/workflows/macOS-11.yml

@@ -21,15 +21,16 @@ on:
       - develop
       - unstable
 
+env:
+  DEVELOPER_DIR: /Applications/Xcode_13.3.1.app/Contents/Developer
+
 jobs:
   spm:
     name: Swift Package Manager 5.5
     runs-on: macOS-12
     concurrency: 
       group: spm-${{ github.run_id }}
       cancel-in-progress: false
-    env:
-      DEVELOPER_DIR: /Applications/Xcode_13.3.1.app/Contents/Developer
     steps:
       - uses: actions/checkout@v2
       - name: Resolve dependencies
@@ -46,14 +47,13 @@ jobs:
         run: swift test --skip-build -c debug --filter localTests
       - name: Run remote tests
         run: swift test --skip-build -c debug --filter remoteTests
+
   carthage-iOS:
     name: Carthage
     runs-on: macOS-12
     concurrency: 
       group: carthage-${{ github.run_id }}
       cancel-in-progress: false
-    env:
-      DEVELOPER_DIR: /Applications/Xcode_13.3.1.app/Contents/Developer
     strategy:
       fail-fast: false
       max-parallel: 2