Bump trio from 0.19.0 to 0.20.0 (#1293)

Bumps [trio](https://github.com/python-trio/trio) from 0.19.0 to 0.20.0.
- [Release notes](https://github.com/python-trio/trio/releases)
- [Commits](python-trio/trio@v0.19.0...v0.20.0)

---
updated-dependencies:
- dependency-name: trio
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

poetry.lock

@@ -68,7 +68,7 @@ typing-extensions = ">=4.0,<5.0"
 [tool.poetry.dev-dependencies]
 anyio = "^3.5"
 curio = "^1.5"
-trio = "^0.19"
+trio = "^0.20"
 attrs = "^21.4"
 httpx = "^0.22"