bpo-35402: Update Windows build to use Tcl and Tk 8.6.9 (GH-11146)

(cherry picked from commit f8e9bd568adf85c1e4aea1dda542a96b027797e2)

Co-authored-by: Steve Dower <steve.dower@microsoft.com>
diff --git a/PCbuild/tcltk.props b/PCbuild/tcltk.props
index 0a59c08..b185cb7 100644
--- a/PCbuild/tcltk.props
+++ b/PCbuild/tcltk.props
@@ -4,7 +4,7 @@
   <PropertyGroup>
     <TclMajorVersion>8</TclMajorVersion>
     <TclMinorVersion>6</TclMinorVersion>
-    <TclPatchLevel>8</TclPatchLevel>
+    <TclPatchLevel>9</TclPatchLevel>
     <TclRevision>0</TclRevision>
     <TkMajorVersion>$(TclMajorVersion)</TkMajorVersion>
     <TkMinorVersion>$(TclMinorVersion)</TkMinorVersion>