Bump poetry from 2.1.4 to 2.2.0 (#1900)

* Bump poetry from 2.1.4 to 2.2.0

Bumps [poetry](https://github.com/python-poetry/poetry) from 2.1.4 to 2.2.0.
- [Release notes](https://github.com/python-poetry/poetry/releases)
- [Changelog](https://github.com/python-poetry/poetry/blob/main/CHANGELOG.md)
- [Commits](python-poetry/poetry@2.1.4...2.2.0)

---
updated-dependencies:
- dependency-name: poetry
  dependency-version: 2.2.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

* Add changelog entry

* Convert some Poetry test fixtures to PEP 735 syntax

Poetry 2.2.0 added support for PEP 735.

In order to test this, some of the Poetry test fixtures now use
dependency groups syntax to specify optional dependencies
rather than Poetry's previous proprietary syntax.

See:
https://github.com/python-poetry/poetry/releases/tag/2.2.0
https://peps.python.org/pep-0735/

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Ed Morley <501702+edmorley@users.noreply.github.com>

Author: dependabot[bot]

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## [Unreleased]
 
+- Updated Poetry from 2.1.4 to 2.2.0. ([#1900](https://github.com/heroku/heroku-buildpack-python/pull/1900))
 - Updated uv from 0.8.15 to 0.8.17. ([#1899](https://github.com/heroku/heroku-buildpack-python/pull/1899))
 
 ## [v307] - 2025-09-10

requirements/poetry.txt

@@ -1 +1 @@
-poetry==2.1.4
+poetry==2.2.0

spec/fixtures/ci_poetry/poetry.lock

@@ -1,9 +1,16 @@
-[tool.poetry]
-package-mode = false
+[project]
+name = "ci-poetry"
+version = "0.0.0"
+requires-python = ">=3.13"
+dependencies = [
+    "typing-extensions",
+]
+
+[dependency-groups]
+dev = [
+    "pytest",
+]
 
-[tool.poetry.dependencies]
-python = "^3.13"
-typing-extensions = "*"
 
-[tool.poetry.group.test.dependencies]
-pytest = "*"
+[tool.poetry]
+package-mode = false

spec/fixtures/ci_poetry/pyproject.toml

@@ -3,12 +3,14 @@ name = "poetry-basic"
 version = "0.0.0"
 requires-python = ">=3.13"
 dependencies = [
-    "typing-extensions"
+    "typing-extensions",
+]
+
+[dependency-groups]
+# This group shouldn't be installed due to us passing `--only main`.
+dev = [
+    "pytest",
 ]
 
 [tool.poetry]
 package-mode = false
-
-# This group shouldn't be installed due to us passing `--only main`.
-[tool.poetry.group.dev.dependencies]
-pytest = "*"