message: refactor(css/parser): Avoid unnecessary checks
diff: @@ -1096,7 +1096,7 @@ where
  }
  }
  - if !is_one_of!(self, EOF, ")", "/") {
  + if !is_one_of!(self, EOF, "/") {
  match function_name {
  "hwb" => {
  let percentage_or_none = self.try_parse_variable_function(
  @@ -1229,7 +1229,7 @@ where
  }
  }
  - if !is_one_of!(self, EOF, ")", "/") {
  + if !is_one_of!(self, EOF, "/") {
  match function_name {
  "hwb" => {
  let percentage_or_none = self.try_parse_variable_function(
  @@ -1416,7 +1416,7 @@ where
  }
  }
  - if !is_one_of!(self, EOF, ")", "/") && function_name == "device-cmyk" {
  + if !is_one_of!(self, EOF, "/") && function_name == "device-cmyk" {
  let cmyk_component = self.try_parse_variable_function(
  |parser, _| Ok(Some(ComponentValue::CmykComponent(parser.parse()?))),
  &mut has_variable,
  