package/ci: drop MSVC 2017 ES builds and RT ES2 build.

Making room for MSVC 2022. GLES will be tested more than enough on 2019
and 2022. The RT port is rarely (if ever) used and obnoxiously slow, so
ES3 has to suffice.

package/ci/appveyor.yml

@@ -52,26 +52,14 @@ environment:
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
     APPVEYOR_JOB_NAME: windows-mingw
     ENABLE_VULKAN: ON
-  - TARGET: desktop-gles
-    TARGET_GLES2: ON
-    APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-    APPVEYOR_JOB_NAME: windows-gles2-msvc2017
   - TARGET: desktop-gles
     TARGET_GLES2: ON
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
     APPVEYOR_JOB_NAME: windows-gles2-msvc2019
-  - TARGET: desktop-gles
-    TARGET_GLES2: OFF
-    APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-    APPVEYOR_JOB_NAME: windows-gles3-msvc2017
   - TARGET: desktop-gles
     TARGET_GLES2: OFF
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
     APPVEYOR_JOB_NAME: windows-gles3-msvc2019
-  - TARGET: rt
-    TARGET_GLES2: ON
-    APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-    APPVEYOR_JOB_NAME: windows-rt-gles2-msvc2017
   - TARGET: rt
     TARGET_GLES2: OFF
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017