Update MetaGraphs requirement from 0.7, 0.8 to 0.7, 0.8, 0.9 in /test

Updates the requirements on [MetaGraphs](https://github.com/JuliaGraphs/MetaGraphs.jl) to permit the latest version.
- [Release notes](https://github.com/JuliaGraphs/MetaGraphs.jl/releases)
- [Commits](https://github.com/JuliaGraphs/MetaGraphs.jl/commits/v0.9.0)

---
updated-dependencies:
- dependency-name: MetaGraphs
  dependency-version: 0.9.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

test/Project.toml

@@ -15,6 +15,6 @@ BenchmarkTools = "1"
 Documenter = "1"
 Graphs = "1.4.1"
 InteractiveUtils = "1"
-MetaGraphs = "0.7, 0.8"
+MetaGraphs = "0.7, 0.8, 0.9"
 SimpleTraits = "0.9"
 Test = "1"