patch 8.2.4983: colors test fails in the GUI

Problem:    Colors test fails in the GUI.
Solution:   Reset g:terminal_ansi_colors.
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 68dbb0a..1a05a59 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -2681,6 +2681,7 @@
     endif
     call assert_fails('call term_start("' .. cmd .. '", #{term_finish: "close"'
         \ .. ', ansi_colors: range(16)})', 'E475:')
+    unlet g:terminal_ansi_colors
   endif
 
   " type()
diff --git a/src/version.c b/src/version.c
index e758e81..1ac4560 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4983,
+/**/
     4982,
 /**/
     4981,