mail/thunderbird: make mouse cursors work again

when no "mouse cursor theme" is configured (using the default X
cursors), the cursor did not change based on context (mouse over, ...).
Import patch from www/firefox to fix this.

mail/thunderbird/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	thunderbird
 DISTVERSION=	128.2.0
-PORTREVISION=	2
+PORTREVISION=	3
 CATEGORIES=	mail news net-im wayland
 MASTER_SITES=	MOZILLA/${PORTNAME}/releases/${DISTVERSION}esr/source \
 		MOZILLA/${PORTNAME}/candidates/${DISTVERSION}esr-candidates/build1/source

mail/thunderbird/files/patch-bug1876366

@@ -0,0 +1,23 @@
+commit 46a89fb0319d673b3139a068e3d89aed9f44fc16
+Author: Christoph Moench-Tegeder <cmt@burggraben.net>
+
+    use gdk legacy cursor interface by default
+    
+    Upstream https://bugzilla.mozilla.org/show_bug.cgi?id=1876366#c16
+    hints that we could re-test this once we have GTK 3.24.42 (with the
+    now-current gtk3-3.24.41 the original problem is still reproducable,
+    but toggling this flag does fix it for me)
+
+diff --git modules/libpref/init/StaticPrefList.yaml modules/libpref/init/StaticPrefList.yaml
+index 835450712a12..f2249006c36d 100644
+--- modules/libpref/init/StaticPrefList.yaml
++++ modules/libpref/init/StaticPrefList.yaml
+@@ -16070,7 +16070,7 @@
+ # Whether to use gtk legacy cursor API.
+ - name: widget.gtk.legacy-cursors.enabled
+   type: bool
+-  value: false
++  value: true
+   mirror: always
+ 
+ # Whether to use gtk high contrast themes to disable content styling like on