perf(python-dotenv): replace findall with str-count in advance

Co-authored-by: Matheus Virgolino <matheus.virgolino.abilio.da.silva@ccc.ufcg.edu.br>
Co-authored-by: Manoel Netto <manoel.da.nobrega.eustaqueo.netto@ccc.ufcg.edu.br>
Co-authored-by: Pedro <pedroalmeida1896@gmail.com>
Co-authored-by: Lucaslg7 <lucasmoizinholg7@gmail.com>
Co-authored-by: RailtonDantas <railtondantas.code@gmail.com>
Co-authored-by: João Pereira <joao.pereira.de.oliveira@ccc.ufcg.edu.br>

Author: 6 people

src/dotenv/parser.py

@@ -59,7 +59,7 @@ def set(self, other: "Position") -> None:
 
     def advance(self, string: str) -> None:
         self.chars += len(string)
-        self.line += len(re.findall(_newline, string))
+        self.line += string.count("\n") + string.count("\r") - string.count("\r\n")
 
 
 class Error(Exception):