Adding Win7/8 deprecation URL

Chromium change:
https://chromium.googlesource.com/chromium/src/+/d4020c8c292ccf6e61e92145ff62beda147711dd

commit d4020c8c292ccf6e61e92145ff62beda147711dd
Author: Jesse McKenna <jessemckenna@google.com>
Date:   Tue Oct 25 21:22:37 2022 +0000

    Add infobar and about:help warnings for Win 7/8.1

    This change adds a notice to warn the user about Chrome no longer
    supporting Windows versions older than 10. This notice appears in an
    infobar when Chrome first launches, as well as above the version
    information at about:help.

    Please see the following for more details (Google internal):
    * screenshots:
    https://drive.google.com/drive/folders/1eSBrMcpHhI6rYoOQ-ITNELDkFsZ6Q9XE?resourcekey=0-q_aEGLWrbyUuPMi4jlmP7A&usp=sharing
    * tracking doc: go/chrome-win-deprecation

    Bug: 1377525

chromium_src/chrome/common/url_constants.cc

@@ -249,7 +249,9 @@ const char kChromeCleanerLearnMoreURL[] =
 
 const char kWindowsXPVistaDeprecationURL[] =
     "https://support.brave.com/";
-#endif
+
+const char kWindows78DeprecationURL[] = "https://support.brave.com/";
+#endif  // BUILDFLAG(IS_WIN)
 
 const char kChromeSyncLearnMoreURL[] = "https://support.brave.com/";