ci: Downgrade minimum iOS version back to 11.0

This was a red herring, the real issue was the build configurations.

ios/Flutter/AppFrameworkInfo.plist

@@ -21,6 +21,6 @@
   <key>CFBundleVersion</key>
   <string>1.0</string>
   <key>MinimumOSVersion</key>
-  <string>12.1</string>
+  <string>11.0</string>
 </dict>
 </plist>

ios/Podfile

@@ -1,4 +1,4 @@
-platform :ios, '12.1'
+platform :ios, '11.0'
 
 ENV['COCOAPODS_DISABLE_STATS'] = 'true'
 
@@ -39,8 +39,5 @@ end
 post_install do |installer|
   installer.pods_project.targets.each do |target|
     flutter_additional_ios_build_settings(target)
-    target.build_configurations.each do |config|
-      config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '12.1'
-    end
   end
 end

ios/Runner.xcodeproj/project.pbxproj

@@ -437,7 +437,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 12.1;
+				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SUPPORTED_PLATFORMS = "iphonesimulator iphoneos";
@@ -572,7 +572,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 12.1;
+				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = iphoneos;
@@ -622,7 +622,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 12.1;
+				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SUPPORTED_PLATFORMS = "iphonesimulator iphoneos";