Run LSP benchmarks in CI (#5546)

## Description

Runs benchmarks in CI with
[criterion-compare-prs](https://github.com/marketplace/actions/criterion-compare-prs)
so the comparison shows as a comment on the PR.

The extra config in `Cargo.toml` is because of this issue:
bheisler/criterion.rs#275. It needs to be
merged to master first (#5547) for
the benchmark comparison to work.

## Checklist

- [ ] I have linked to any relevant issues.
- [ ] I have commented my code, particularly in hard-to-understand
areas.
- [ ] I have updated the documentation where relevant (API docs, the
reference, and the Sway book).
- [ ] I have added tests that prove my fix is effective or that my
feature works.
- [ ] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [ ] I have done my best to ensure that my PR adheres to [the Fuel Labs
Code Review
Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md).
- [ ] I have requested a review from the relevant team or maintainers.

.github/workflows/bench-lsp.yml

@@ -0,0 +1,26 @@
+name: Benchmark LSP
+
+on:
+  pull_request:
+    draft: false
+    paths:
+      - forc-plugins/forc-lsp/**
+      - sway-lsp/**
+      - forc-pkg/**
+      - sway-core/**
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  compare-master:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: Swatinem/rust-cache@v2
+      - uses: actions/checkout@v3
+      - uses: boa-dev/[email protected]
+        with:
+          cwd: "./sway-lsp"
+          branchName: ${{ github.base_ref }}
+          token: ${{ secrets.GITHUB_TOKEN }}

sway-lsp/README.md

@@ -16,7 +16,6 @@ This extension provides LSP support for the Sway smart contract programming lang
 - code actions
 - imports insertion
 
-
 _Coming Soon_
 - code completion
 - apply suggestions from errors