Tclint

- Update `tclfmt` to strip trailing whitespace from comments
- Update `tclsp` to support reading configuration from user-supplied paths

This release contains no changes to documented user-facing behavior. It reverts some changes to the plugin system that added a dependency incompatible with the VS Code extension's current approach to bundling Python dependencies.

- Fix bug that may cause language server formatting to duplicate lines at end of file
- Change default max line length from 80 characters to 100

This release fixes two parser issues:

- Fix `tclfmt` crash when encountering an arg expansion pattern (`{*}`) followed by a semicolon or close bracket (thanks to L2523)
- Improve error message when trying to parse non-concrete values as lists (e.g. `proc foo [list a b] { }`) (thanks to AlaoPrado)

This release is also the first to contain contributions from others 🥳 Thank you both for helping to improve `tclint`!

This release has three major changes:

- The project now includes a language server, `tclsp`!
- This is an LSP-based language server that enables `tclint` editor integration supporting diagnostics and formatting. See the [docs](https://github.com/nmoroze/tclint/blob/main/docs/lsp.md) for more info.
- Style checks have been removed from `tclint`.
- This removes the `--no-check-style` flag and makes its behavior the default.
- Support has been dropped for Python 3.8, which is now EOL.

Detailed user-facing changes

- Installing the `tclint` PyPI package adds a `tclsp` binary to your path. There should be no need to run this directly; in most cases your editor will be configured to launch it for you.
- No more style-specific rules. References to these must be removed from config files.
- No more `style.allow-aligned-sets` config setting, since `tclfmt` doesn't respect it. This must be removed from config files.
- All the style-related configuration flags have been removed from the `tclint` CLI.
- The `--no-check-style` flag has been removed from the `tclint` CLI, its behavior is now the default.
- The `--show-categories` flag has been removed from the `tclint` CLI. The category separation isn't meaningful now that style checks have been removed.
- The reported positions of some violations have changed.

This release fixes a handful of minor bugs.

- Fix crash on `expr` or `proc` commands that have no arguments
- Fix bug in handling of unintended exceptions in command argument handlers, they're now caught gracefully
- Fix some missing syntax error handling in expressions (e.g. erroring out on an unbalanced closed paren)
- Fix incorrect position recorded for a single-item list that isn't enclosed in braces or quotes