bug: new `attr()` syntax with `<attr-datatype>` emits a warning

[marchbox]

Did you check existing issues?

• I have read all the tree-sitter docs if it relates to using the parser
• I have searched the existing issues of tree-sitter-css

Tree-Sitter CLI Version, if relevant (output of tree-sitter --version)

No response

Describe the bug

CSS' attr() function has an updated syntax, which allows developers to define the type when parsing the value of an attribute:

inline-size: attr(data-progress type(<percentage>), 0%);

https://developer.mozilla.org/en-US/docs/Web/CSS/attr

Currently, when tree-sitter-css parses a CSS file, the < and > in the following line cause a warning:

@supports (inline-size: attr(data-progress type(<percentage>), 0%)) {

Invalid CSS from line A column B to line X column Y

Steps To Reproduce/Bad Parse Tree

Parse the following code:

@supports (inline-size: attr(data-progress type(<percentage>), 0%)) {
  .progress-bar {
    inline-size: attr(data-progress type(<percentage>), 0%)
  }
}

Expected Behavior/Parse Tree

The parser should not emit a warning.

Repro

@supports (inline-size: attr(data-progress type(<percentage>), 0%)) {
  .progress-bar {
    inline-size: attr(data-progress type(<percentage>), 0%)
  }
}