patch 8.2.3092: Vim9: builtin function test fails without +channel feature

Problem:    Vim9: builtin function test fails without the +channel feature.
Solution:   Check the +channel feature is supported. (Dominique Pellé,
            closes #8507)

runtime/doc/eval.txt

@@ -8219,6 +8219,8 @@ prompt_getprompt({buf})					*prompt_getprompt()*
 		Can also be used as a |method|: >
 			GetBuffer()->prompt_getprompt()
 
+<		{only available when compiled with the |+channel| feature}
+
 
 prompt_setcallback({buf}, {expr})			*prompt_setcallback()*
 		Set prompt callback for buffer {buf} to {expr}.  When {expr}
@@ -8252,6 +8254,7 @@ prompt_setcallback({buf}, {expr})			*prompt_setcallback()*
 <		Can also be used as a |method|: >
 			GetBuffer()->prompt_setcallback(callback)
 
+<		{only available when compiled with the |+channel| feature}
 
 prompt_setinterrupt({buf}, {expr})			*prompt_setinterrupt()*
 		Set a callback for buffer {buf} to {expr}.  When {expr} is an
@@ -8265,6 +8268,8 @@ prompt_setinterrupt({buf}, {expr})			*prompt_setinterrupt()*
 		Can also be used as a |method|: >
 			GetBuffer()->prompt_setinterrupt(callback)
 
+<		{only available when compiled with the |+channel| feature}
+
 prompt_setprompt({buf}, {text})				*prompt_setprompt()*
 		Set prompt for buffer {buf} to {text}.  You most likely want
 		{text} to end in a space.
@@ -8275,6 +8280,8 @@ prompt_setprompt({buf}, {text})				*prompt_setprompt()*
 		Can also be used as a |method|: >
 			GetBuffer()->prompt_setprompt('command: ')
 
+<		{only available when compiled with the |+channel| feature}
+
 prop_ functions are documented here: |text-prop-functions|
 
 pum_getpos()						*pum_getpos()*

src/testdir/test_vim9_builtin.vim

@@ -1344,8 +1344,10 @@ def Test_prevnonblank()
 enddef
 
 def Test_prompt_getprompt()
-  CheckDefFailure(['prompt_getprompt([])'], 'E1013: Argument 1: type mismatch, expected string but got list<unknown>')
-  assert_equal('', prompt_getprompt('NonExistingBuf'))
+  if has('channel')
+    CheckDefFailure(['prompt_getprompt([])'], 'E1013: Argument 1: type mismatch, expected string but got list<unknown>')
+    assert_equal('', prompt_getprompt('NonExistingBuf'))
+  endif
 enddef
 
 def Test_rand()

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3092,
 /**/
     3091,
 /**/