fix(parser): remove unused ParseError type

ParseError and NewParseError were defined in internal/parser/types.go
but never raised by Parse() or splitAndClassify(), which always return
plain fmt.Errorf strings. No caller checked for ParseError via
errors.As or type assertions either.

The parser delegates to pglex tokenization which doesn't produce parse
errors, so the type had no path to being used. Remove the dead code.

Author: pashagolub

internal/parser/types.go

@@ -1,33 +1,9 @@
 package parser
 
 import (
-	"fmt"
-
 	"github.com/cybertec-postgresql/pgcov/internal/discovery"
 )
 
-// ParseError represents SQL parsing failure
-type ParseError struct {
-	File    string
-	Line    int
-	Column  int
-	Message string
-}
-
-func (e *ParseError) Error() string {
-	return fmt.Sprintf("%s:%d:%d: %s", e.File, e.Line, e.Column, e.Message)
-}
-
-// NewParseError creates a new ParseError
-func NewParseError(file string, line, column int, message string) *ParseError {
-	return &ParseError{
-		File:    file,
-		Line:    line,
-		Column:  column,
-		Message: message,
-	}
-}
-
 // ParsedSQL represents a successfully parsed SQL file
 type ParsedSQL struct {
 	File       *discovery.DiscoveredFile