runtime(osc52): Omit paste from the osc52 provider when g:osc52_disable_paste is enabled

Omit paste capability from the osc52 provider when g:osc52_disable_paste
is enabled This avoids OSC 52 paste queries on unsupported terminals and
prevents the +/* registers from being treated as empty. Documentation
updated accordingly.

related: #18983
closes:  #19542

Signed-off-by: mikoto2000 <mikoto2000@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/pack/dist/opt/osc52/doc/osc52.txt

@@ -62,9 +62,10 @@ setting |g:osc52_force_avail| to true.
 
                                                         *g:osc52_disable_paste*
 If your terminal does not support pasting via OSC 52, or has it disabled, then
-it is a good idea to set g:osc52_disable_paste to TRUE.  This will cause an
-empty string to be returned when Vim attempts to query the osc52.vim provider,
-instead of doing a blocking wait, as said in |osc52-support|.
+it is a good idea to set g:osc52_disable_paste to TRUE.  This will register
+only the "copy" method for the osc52.vim clipboard provider, so Vim will not
+attempt an OSC 52 paste query and avoids the blocking wait described in
+|osc52-support|.
 
 ==============================================================================
 vim:tw=78:ts=8:fo=tcq2:ft=help:

runtime/pack/dist/opt/osc52/plugin/osc52.vim

@@ -3,7 +3,7 @@ vim9script
 # Vim plugin for OSC52 clipboard support
 #
 # Maintainer:	The Vim Project <https://github.com/vim/vim>
-# Last Change:	2025 Dec 18
+# Last Change:	2026 Mar 01
 
 if !has("timers")
   finish
@@ -11,18 +11,25 @@ endif
 
 import autoload "../autoload/osc52.vim" as osc
 
-v:clipproviders["osc52"] = {
+var provider: dict<any> = {
   "available": osc.Available,
-  "paste": {
-    "*": osc.Paste,
-    "+": osc.Paste
-  },
   "copy": {
     "*": osc.Copy,
     "+": osc.Copy
   },
 }
 
+if !get(g:, 'osc52_disable_paste', 0)
+  provider->extend({
+    "paste": {
+      "*": osc.Paste,
+      "+": osc.Paste
+    }
+  })
+endif
+
+v:clipproviders["osc52"] = provider
+
 def SendDA1(): void
   if !has("gui_running") && !get(g:, 'osc52_force_avail', 0)
       && !get(g:, 'osc52_no_da1', 0)