Make `from_slice_delim` (expression parser) non-recursive

Sorry if it's a dumb question, as far as I understand there is a recursion depth limit on from_slice_delim to avoid running out of stack space (based on https://github.com/sipa/miniscript/pull/5) when parsing an expression with round brackets. However, the parse function from sipa/miniscript is not recursive anymore (https://github.com/sipa/miniscript/pull/68). Worths make it non-recursive here as well? I noticed that some miniscripts that can be parsed on Core fails here because of this limit.

// https://github.com/sipa/miniscript/pull/5 for discussion on this number
const MAX_RECURSION_DEPTH: u32 = 402;

impl<'a> Tree<'a> {
    /// Parse an expression with round brackets
    pub fn from_slice(sl: &'a str) -> Result<(Tree<'a>, &'a str), Error> {
        // Parsing TapTree or just miniscript
        Self::from_slice_delim(sl, 0u32, '(')
    }

    pub(crate) fn from_slice_delim(
        mut sl: &'a str,
        depth: u32,
        delim: char,
    ) -> Result<(Tree<'a>, &'a str), Error> {
        if depth >= MAX_RECURSION_DEPTH {
            return Err(Error::MaxRecursiveDepthExceeded);
        }

Start at Tree::from_slice_delim and review the linked sipa/miniscript parser change for how recursion was removed. The work is done when deeply nested miniscripts that Core accepts can be parsed here without the current recursion-depth failure, while existing parsing behavior remains intact.