Exclude cefpython3 other-Python-version .pyd and GStreamer from build

- Added kivy.lib.gstplayer to excluded_imports (we use ffpyplayer)
- Added all cefpython3_py{27,34-311}.pyd to excluded_imports
- Removes ~300 lines of library-not-found warnings from build output
- Reduces .exe size from 143 MB to 96 MB

windows/build.spec

@@ -112,6 +112,18 @@ excluded_imports = [
     'gi',  # GTK introspection (Linux)
     'gi.repository',
     'evdev',  # We inject a fake evdev module in run_win.py
+    # GStreamer — we use ffpyplayer, not GStreamer
+    'kivy.lib.gstplayer',
+    # cefpython3: keep only Python 3.12 .pyd, exclude other version .pyd files
+    'cefpython3.cefpython_py27',
+    'cefpython3.cefpython_py34',
+    'cefpython3.cefpython_py35',
+    'cefpython3.cefpython_py36',
+    'cefpython3.cefpython_py37',
+    'cefpython3.cefpython_py38',
+    'cefpython3.cefpython_py39',
+    'cefpython3.cefpython_py310',
+    'cefpython3.cefpython_py311',
 ]
 
 # --- Application data files to bundle --------------------------------