[3.12] gh-106969: Indicate no modules were added in 3.10 & 3.12 (GH-106988) (#107094)

The "New Modules" section was left in place to ensure that the anchor
link for new modules will still exist:

/whatsnew/3.12.htmlGH-new-modules
/whatsnew/3.10.htmlGH-new-modules

This means that existing links to this section don't break.
(cherry picked from commit 6dbffae)

Co-authored-by: Sebastiaan Zeeff <[email protected]>

Author: zormit

Doc/whatsnew/3.10.rst

@@ -887,7 +887,7 @@ Other Language Changes
 New Modules
 ===========
 
-* None yet.
+* None.
 
 
 Improved Modules

Doc/whatsnew/3.12.rst

@@ -486,7 +486,7 @@ Other Language Changes
 New Modules
 ===========
 
-* None yet.
+* None.
 
 
 Improved Modules