patch 8.2.3782: Vim9: no error if a function shadows a script variable

Problem:    Vim9: no error if a function shadows a script variable.
Solution:   Check the function doesn't shadow a variable. (closes #9310)
diff --git a/src/evalvars.c b/src/evalvars.c
index d91ec01..0410259 100644
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -2712,7 +2712,7 @@
 		type = sv->sv_type;
 	    }
 	}
-	else if (in_vim9script())
+	else if (in_vim9script() && (flags & EVAL_VAR_NO_FUNC) == 0)
 	{
 	    ufunc_T *ufunc = find_func(name, FALSE, NULL);