Update Suppressor requirement to 0.2.8 in /docs

Updates the requirements on [Suppressor](https://github.com/JuliaIO/Suppressor.jl) to permit the latest version.
- [Release notes](https://github.com/JuliaIO/Suppressor.jl/releases)
- [Commits](JuliaIO/Suppressor.jl@v0.0.1...v0.2.8)

---
updated-dependencies:
- dependency-name: Suppressor
  dependency-version: 0.2.8
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

docs/Project.toml

@@ -18,3 +18,4 @@ Documenter = "1.16.1"
 Latexify = "0.16.10"
 Plots = "1.41.3"
 StatsPlots = "0.15.8"
+Suppressor = "0.2.8"