fix(compose): dedup pyproject.toml optional-dependencies after P2+P3 merge

The 'git merge origin/main' auto-merged both P2 and P3 dev-deps blocks
into one pyproject.toml with two [project.optional-dependencies] sections
(tomltools refuses to parse that). Drop the second copy; both blocks
listed the same pytest + pytest-asyncio pair, just in different order.

Caught by 'python -m pytest' exiting 1 with a TOMLDecodeError before any
test ran.

pyproject.toml

@@ -30,12 +30,6 @@ dev = [
 [project.scripts]
 damascus = "damascus.cli:main"
 
-[project.optional-dependencies]
-dev = [
-  "pytest-asyncio>=0.23",
-  "pytest>=7",
-]
-
 [build-system]
 requires = ["setuptools>=68"]
 build-backend = "setuptools.build_meta"