Update docs for Tcl 9.0 changes

CHANGES.current

@@ -23,6 +23,10 @@ Version 4.2.1 (in progress)
 	    Warning 202: Could not evaluate expression 'MY_VERSION_AT_LEAST(1,2,3)'
 	    Warning 202: Syntax error: expected operator
 
+2024-01-11: PaulObermeier
+	    [Tcl] Improve support for Tcl 9.0.  All examples and tests now pass
+	    with Tcl 9.0.b1.
+
 2024-01-06: wsfulton
             [Python] #2744 Regression fix - add in missing SwigPyIterator_T fragment for
             SwigPyIteratorClosed_T when using %import on an instantiated std::map.

Doc/Manual/Tcl.html

@@ -81,7 +81,7 @@
 <p>
 This chapter discusses SWIG's support of Tcl. Since SWIG 4.1.0, Tcl 8.4 or a
 later release is required.  Prior to that earlier Tcl 8.x releases were also
-supported.
+supported.  Tcl 9.0 is supported since SWIG 4.2.1.
 </p>
 
 <H2><a name="Tcl_nn2">37.1 Preliminaries</a></H2>

RELEASENOTES

@@ -7,6 +7,9 @@ Release Notes
 Detailed release notes are available with the release and are also
 published on the SWIG web site at https://swig.org/release.html.
 
+SWIG-4.2.1 summary:
+- Tcl 9.0 support.
+
 SWIG-4.2.0 summary:
 - Various template wrapping improvements: template template parameters,
   variadic templates, partially specialized templates, const template