"pure" before function declaration/definition is flagged as unexpected

[andrsmllr]

With the VHDL LS plugin (0.3.1) of VisualStudioCode (1.47.3) the VHDL keyword pure is flagged as unexpected before the function keyword. A list of expected keywords is shown. The keyword impure is among the ones suggest, which I consider mildly ironic.
The keyword pure is optional but correct in this position (the only position where pure can actually appear at all I guess) and should not be flagged.

According to the plugin's description "As VHDL LS uses the Rust HDL language server, issues related to syntax and semantic checks should be reported directly to Rust HDL".

[FFFFFFFXXXXXXX]

Seems like the Keyword "Pure" is missing? https://github.com/kraigher/rust_hdl/blob/master/vhdl_lang/src/syntax/tokens/tokenizer.rs

Not sure if related, but adding pure / impure before a function makes the function have the wrong syntax highlighting.
wrong:

correct: