package/ci: ah yes, Xcode images rotting away right under my very hands.

TBF I have to thank CircleCI for sending me no less than three warning
e-mails about Xcode image deprecation. I just didn't bother
updating until it started actually failing.

package/ci/circleci.yml

@@ -10,12 +10,12 @@ executors:
   ubuntu-18_04:
     docker:
     - image: ubuntu:bionic-20200921
-  xcode-11_2:
+  xcode-11_4:
     # Molten-vk isn't in (non-updated) Homebrew on the 9.4 or 10.0/1/2 image,
     # have to use 10.3 instead; since 2021-06-08 it refuses to work on 10.14 so
-    # have to use 11.2 at least
+    # have to use 11.2 at least; since 2022-01-20 the oldest 11 image is 11.4.
     macos:
-      xcode: 11.2.1
+      xcode: 11.4.1
   xcode-11_6:
     macos:
       xcode: 11.6.0
@@ -393,7 +393,7 @@ jobs:
         script: unix-desktop.sh
 
   macos-gl:
-    executor: xcode-11_2
+    executor: xcode-11_4
     environment:
       CMAKE_CXX_FLAGS: --coverage
       CONFIGURATION: Debug
@@ -406,7 +406,7 @@ jobs:
     - lcov
 
   macos-gles3:
-    executor: xcode-11_2
+    executor: xcode-11_4
     environment:
       CMAKE_CXX_FLAGS: --coverage
       CONFIGURATION: Debug
@@ -441,10 +441,7 @@ jobs:
     - lcov
 
   macos-static:
-    # Molten-vk isn't in (non-updated) Homebrew on the 9.4 or 10.0/1/2 image,
+    executor: xcode-11_4
-    # have to use 10.3 instead; since 2021-06-08 it refuses to work on 10.14 so
-    # have to use 11.2 at least
-    executor: xcode-11_2
     environment:
       # STUPID yml interprets unquoted ON as a boolean
       BUILD_STATIC: "ON"