Delete definition of GetOsVersion()

I deleted the declaration of this function in
https://webrtc-review.googlesource.com/c/src/+/234160 but forgot to
delete the definition.

This now actually happens to remove one call to GetVersionEx.

No behavior change.

Bug: chromium:1255114
Change-Id: I65b61a362da9b6d41c16a9da23781d5a1ccf885f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/235080
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/main@{#35196}
diff --git a/rtc_base/win32.cc b/rtc_base/win32.cc
index 8d8fe27..b44e513 100644
--- a/rtc_base/win32.cc
+++ b/rtc_base/win32.cc
@@ -311,28 +311,4 @@
   return 1;
 }
 
-// Windows UWP applications cannot obtain versioning information from
-// the sandbox with intention (as behehaviour based on OS versioning rather
-// than feature discovery / compilation flags is discoraged and Windows
-// 10 is living continously updated version unlike previous versions
-// of Windows).
-#if !defined(WINUWP)
-
-bool GetOsVersion(int* major, int* minor, int* build) {
-  OSVERSIONINFO info = {0};
-  info.dwOSVersionInfoSize = sizeof(info);
-  if (GetVersionEx(&info)) {
-    if (major)
-      *major = info.dwMajorVersion;
-    if (minor)
-      *minor = info.dwMinorVersion;
-    if (build)
-      *build = info.dwBuildNumber;
-    return true;
-  }
-  return false;
-}
-
-#endif  // !defined(WINUWP)
-
 }  // namespace rtc