Comment lexing misses trailing `/` for multi-line comments

[kayagokalp]

Comment lexing works perfectly while the comments are single-line comments like the following:

// This is a comment

but if the comments are in the form of multiline we are missing the trailing / in the comment's span. So for this example:

/*This is a comment*/

.span().as_str() returns /*This is a comment*

I feel like this shouldn't be hard to tackle so added the "good first issue" label but I did not touch lexer enough to be sure about that so please remove it if that is not the case 🙌 .

Depending on the discussion at #2311 (comment) I can either fix it in #2311 or take a look at this after that is merged.

Related to #2311 (comment)

[mitchmindtree]

I'll address this now 👍