Disable SyncTERM-MSVC build

<@Deuce> SyncTERM on MSVC really shouldn't be part of CI since it's not expected to work.
<DigitalMan> why not?
<@Deuce> Because it's not supported.
<@Deuce> So it's not part of the integration path.

.gitlab-ci.yml

@@ -82,7 +82,7 @@ sexpots-windows:
     paths:
       - "src/sexpots/Release/*.exe"
 
-syncterm-msvc:
+.syncterm-msvc:
   tags: [Windows]
   stage: build
   extends: .rules