🧪 Switch macOS 13.2 to 12.0 in CI (#80145)

* 🧪 Switch macOS 13.2 to 12.0 in CI

The former revealed unexpected flakiness while the latter is the
previous value that was used to be stable. This is a temporary revert.

* Skip lookup_url integration test under macOS 12.0

.azure-pipelines/azure-pipelines.yml

@@ -87,8 +87,8 @@ stages:
       - template: templates/matrix.yml  # context/target
         parameters:
           targets:
-            - name: macOS 13.2
-              test: macos/13.2
+            - name: macOS 12.0
+              test: macos/12.0
             - name: RHEL 7.9
               test: rhel/7.9
             - name: RHEL 8.7 py36
@@ -107,8 +107,8 @@ stages:
       - template: templates/matrix.yml  # context/controller
         parameters:
           targets:
-            - name: macOS 13.2
-              test: macos/13.2
+            - name: macOS 12.0
+              test: macos/12.0
             - name: RHEL 8.7
               test: rhel/8.7
             - name: RHEL 9.1

test/integration/targets/lookup_url/aliases

@@ -1,7 +1,7 @@
 destructive
 shippable/posix/group3
 needs/httptester
-skip/macos/13.2  # This test crashes Python due to https://wefearchange.org/2018/11/forkmacos.rst.html
+skip/macos/12.0  # This test crashes Python due to https://wefearchange.org/2018/11/forkmacos.rst.html
 # Example failure:
 #
 # TASK [lookup_url : Test that retrieving a url works] ***************************