ci(ios): drop macos 10.15 & iOS 12 (#241)

diff --git a/.github/workflows/ios.yml b/.github/workflows/ios.yml
index 142ab9f..982fe8e 100644
--- a/.github/workflows/ios.yml
+++ b/.github/workflows/ios.yml
@@ -49,15 +49,11 @@
     strategy:
       matrix:
         versions:
-          - os-version: macos-10.15
-            ios-version: 12.x
-            xcode-version: 11.x
-
-          - os-version: macos-10.15
+          - os-version: macos-11
             ios-version: 13.x
             xcode-version: 11.x
 
-          - os-version: macos-10.15
+          - os-version: macos-11
             ios-version: 14.x
             xcode-version: 12.x
 
@@ -87,19 +83,8 @@
           npm i -g cordova@latest ios-deploy@latest
           npm ci
 
-      # Starting from Cordova-iOS 6.1, Xcode 11.x or higher is required for a successful build.
-      # By default, the Xcode 11.x app comes with the iOS 13.x.
-      # To continue testing iOS 12.x, we create a symbolic link to the iOS 12.4 Simulator Runtime.
-      # This simulator runtime is located in the Xcode 10.3 app that is preinstalled with the
-      # GitHub’s macOS 10.15 image.
-      - name: Run setup iOS 12.x support
-        if: ${{ matrix.versions.ios-version == '12.x' }}
-        run: |
-          sudo mkdir -p /Library/Developer/CoreSimulator/Profiles/Runtimes
-          sudo ln -s /Applications/Xcode_10.3.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/CoreSimulator/Profiles/Runtimes/iOS.simruntime /Library/Developer/CoreSimulator/Profiles/Runtimes/iOS\ 12.4.simruntime
-
       - name: Run paramedic install
-        if: ${{ endswith(env.repo, '/cordova-paramedic') != true }}
+        if: ${{ endswith(env.repo, '/cordova-paramedic') != true }}
         run: npm i -g github:apache/cordova-paramedic
 
       - name: Run paramedic tests