scanner: remove redundancy from the message suggesting to use quotes instead of backticks for characters

vlib/v/scanner/scanner.v

@@ -1640,19 +1640,16 @@ pub fn (mut s Scanner) ident_char() string {
 				s.error_with_pos('invalid character literal `${orig}` => `${c}` ([${err_info.join(', ')}]) (escape sequence did not refer to a singular rune)',
 					lspos)
 			} else if u.len == 0 {
-				s.add_error_detail_with_pos('use quotes for strings, backticks for characters',
-					lspos)
+				s.add_error_detail('use quotes for strings, backticks for characters')
 				s.error_with_pos('invalid empty character literal `${orig}`', lspos)
 			} else {
-				s.add_error_detail_with_pos('use quotes for strings, backticks for characters',
-					lspos)
+				s.add_error_detail('use quotes for strings, backticks for characters')
 				s.error_with_pos('invalid character literal `${orig}` => `${c}` ([${err_info.join(', ')}]) (more than one character)',
 					lspos)
 			}
 		}
 	} else if c.ends_with('\n') {
-		s.add_error_detail_with_pos('use quotes for strings, backticks for characters',
-			lspos)
+		s.add_error_detail('use quotes for strings, backticks for characters')
 		s.error_with_pos('invalid character literal, use \`\\n\` instead', lspos)
 	} else if c.len > len {
 		ch := c[c.len - 1]

vlib/v/scanner/tests/empty_character_literal_err.out

@@ -4,10 +4,4 @@ vlib/v/scanner/tests/empty_character_literal_err.vv:2:7: error: invalid empty ch
       |          ^
     3 |     println(a)
     4 | }
-Details:
-vlib/v/scanner/tests/empty_character_literal_err.vv:2:7: details: use quotes for strings, backticks for characters
-    1 | fn main() {
-    2 |     a := ``
-      |          ^
-    3 |     println(a)
-    4 | }
+Details: use quotes for strings, backticks for characters

vlib/v/scanner/tests/invalid_character_literal_err_1.out

@@ -1,7 +1,4 @@
 vlib/v/scanner/tests/invalid_character_literal_err_1.vv:1:6: error: invalid character literal `\n\t` => `\n\t` ([`\n`, `\t`]) (more than one character)
     1 | a := `\n\t`
       |      ^
-Details: 
-vlib/v/scanner/tests/invalid_character_literal_err_1.vv:1:6: details: use quotes for strings, backticks for characters
-    1 | a := `\n\t`
-      |      ^
+Details: use quotes for strings, backticks for characters

vlib/v/scanner/tests/invalid_character_literal_err_2.out

@@ -1,7 +1,4 @@
 vlib/v/scanner/tests/invalid_character_literal_err_2.vv:1:6: error: invalid character literal `\nb` => `\nb` ([`\n`, `b`]) (more than one character)
     1 | a := `\nb`
       |      ^
-Details: 
-vlib/v/scanner/tests/invalid_character_literal_err_2.vv:1:6: details: use quotes for strings, backticks for characters
-    1 | a := `\nb`
-      |      ^
+Details: use quotes for strings, backticks for characters

vlib/v/scanner/tests/newline_character_literal_err.out

@@ -4,10 +4,4 @@ vlib/v/scanner/tests/newline_character_literal_err.vv:2:7: error: invalid charac
       |          ^
     3 | `
     4 |     println(a)
-Details:
-vlib/v/scanner/tests/newline_character_literal_err.vv:2:7: details: use quotes for strings, backticks for characters
-    1 | fn main() {
-    2 |     a := `
-      |          ^
-    3 | `
-    4 |     println(a)
+Details: use quotes for strings, backticks for characters

vlib/v/scanner/tests/unknown_escape_sequence_in_ident_char_1_err.out

@@ -4,10 +4,4 @@ vlib/v/scanner/tests/unknown_escape_sequence_in_ident_char_1_err.vv:2:6: error:
       |         ^
     3 | `
     4 | }
-Details: 
-vlib/v/scanner/tests/unknown_escape_sequence_in_ident_char_1_err.vv:2:6: details: use quotes for strings, backticks for characters
-    1 | fn main() {
-    2 |     _ = `\
-      |         ^
-    3 | `
-    4 | }
+Details: use quotes for strings, backticks for characters