Use Python 3.7.5 in CI (#8297)

* Use Python 3.7.5
* Don't specify minor version

Author: kimadeline

build/ci/templates/globals.yml

@@ -1,5 +1,5 @@
 variables:
-  PythonVersion: '3.7.5' # Always use latest version.
+  PythonVersion: '3.7' # Always use latest version.
   NodeVersion: '10.11.0' # Check version of node used in VS Code.
   NpmVersion: '6.10.3'
   MOCHA_FILE: '$(Build.ArtifactStagingDirectory)/test-junit.xml' # All test files will write their JUnit xml output to this file, clobbering the last time it was written.

build/ci/templates/jobs/uitest.yml

@@ -95,7 +95,7 @@ parameters:
       # All scenarios tagged with `@noNeedToTestInAllPython`, will run in the latest version of Python.
       # When using other versions of Python, ignore `@noNeedToTestInAllPython`.
       {
-          "version": "3.7.5",
+          "version": "3.7",
           "displayName": "37",
           "excludeTags": "not @python3.6 and not @python3.5 and not @python2"
       },

news/2 Fixes/8296.md

@@ -0,0 +1 @@
+Fix CI to use Python 3.7.5.