fix: trailing whitespaces are allowed for local_time (#3)

Input:

(each `·` indicates a whitespace)

```toml
valid·=·1979-05-27·
```

Output:

```
# before

(file
  (ERROR
    (key)))

# after

(file
  (pair
    (key) (local_date)))
```

.editorconfig

@@ -7,3 +7,6 @@ indent_size = 2
 indent_style = space
 insert_final_newline = true
 trim_trailing_whitespace = true
+
+[corpus/*]
+trim_trailing_whitespace = false

corpus/custom.txt

@@ -64,7 +64,7 @@ invalid2 = 1979-05-27 T 07:32:00 Z
 
 (file
   (ERROR
-    (key) (ERROR) (local_time) (local_time)
+    (key) (local_date) (local_time) (local_time)
   )
 )
 
@@ -78,11 +78,22 @@ invalid2 = 1979-05-27 T 07:32:00
 --------------------------------------------------------------------------------
 
 (file
-  (pair
-    (key) (ERROR) (local_time)
+  (ERROR
+    (key) (local_date) (local_time) (local_time)
   )
+)
+
+================================================================================
+VALID - local date - trailing whitespaces are allowed
+================================================================================
+
+valid = 1979-05-27 
+
+--------------------------------------------------------------------------------
+
+(file
   (pair
-    (key) (ERROR) (local_time)
+    (key) (local_date)
   )
 )
 

grammar.js

@@ -153,18 +153,14 @@ module.exports = grammar({
     boolean: $ => /true|false/,
 
     offset_date_time: $ =>
-      seq(
+      concatRegex(
         rfc3339_date,
-        token.immediate(rfc3339_delimiter),
-        token.immediate(rfc3339_time),
-        token.immediate(rfc3339_offset)
+        rfc3339_delimiter,
+        rfc3339_time,
+        rfc3339_offset
       ),
     local_date_time: $ =>
-      seq(
-        rfc3339_date,
-        token.immediate(rfc3339_delimiter),
-        token.immediate(rfc3339_time)
-      ),
+      concatRegex(rfc3339_date, rfc3339_delimiter, rfc3339_time),
     local_date: $ => rfc3339_date,
     local_time: $ => rfc3339_time,