ci: resolve the declared dependency floors on every matrix entry

[lesnik512]

Adds the floors job the org standard requires (standard.md §7), following modern-di-fastapi#56. This repo surfaced four separate problems, three of them in the shipped extras.

1. The pydantic extra could not install on 3.12 or 3.13

pydantic>=2.0 resolves to pydantic 2.0, whose pydantic-core has no cp312 wheel:

error: Distribution `pydantic-core==2.0.1` can't be installed because it is
marked as `--no-build` but has no binary distribution

The existing >=2.12 bound for 3.14 had the right idea; the gap below it was unguarded. Bisected on each interpreter — 2.0 fails and 2.1 passes on 3.12; 2.7 and 2.8 fail and 2.8.1 passes on 3.13:

"pydantic>=2.0,<3.0; python_version < '3.12'",
"pydantic>=2.1,<3.0; python_version == '3.12'",
"pydantic>=2.8.1,<3.0; python_version == '3.13'",
"pydantic>=2.12,<3.0; python_version >= '3.14'",

2. The msgspec extra could not install on 3.13

Same shape. msgspec>=0.18.5 is correct for the can_decode reason the comment gives, but 0.19.0 is the first release with a cp313 wheel, and the < '3.14' band swallowed 3.13:

"msgspec>=0.18.5; python_version < '3.13'",
"msgspec>=0.19; python_version == '3.13'",
"msgspec>=0.20; python_version >= '3.14'",

3. hypothesis could not import on 3.14

hypothesis was unbounded in [dependency-groups], so the floors leg resolved 6.0.0, which calls importlib_metadata.entry_points().get(...) — removed from importlib.metadata long ago, fatal on 3.14:

AttributeError: 'EntryPoints' object has no attribute 'get'

Floored at >=6.20, verified: 6.5.0 and 6.10.0 fail, 6.20.0 passes.

4. --no-install-project breaks the isolation tests here

Worth flagging beyond this repo. httpware is the only src-layout package in the org, and [tool.pytest.ini_options] pythonpath = ["src"] is what makes import httpware work without an installed copy. That setting applies to the pytest process only. tests/test_optional_extras_isolation.py and tests/test_optional_extras_pydantic_missing.py deliberately spawn a fresh interpreter, which inherits none of it, and --no-install-project leaves nothing installed to fall back on:

ModuleNotFoundError: No module named 'httpware'

Four tests failed for a reason that has nothing to do with floors. Setting PYTHONPATH: src on the step gives the child the same path pytest gives the parent. --no-install-project cannot be dropped — it is what makes --no-build usable at all, since --no-build otherwise refuses to build this project too.

Why the job exists

pytest resolves every dependency at its newest, so the bottom of each declared range ships unexercised. This job resolves direct dependencies at their floors, wheel-only, on every entry of the same matrix pytest uses, and runs the suite against them. The matrix here folds in 3.14t, which pytest covers through the separate pytest-freethreaded job — §7 asks for every matrix entry, and free-threaded wheel coverage differs from the GIL build's.

Verification

818 passed at the floors on 3.11, 3.12, 3.13, 3.14 and 3.14t. The job installs httpx2==2.0.0, pydantic==2.8.1, msgspec==0.19.0 and opentelemetry-api==1.20.0 on 3.13 — each exactly at its declared bound, confirmed by reading back the install list rather than assuming. Resolved-newest path re-checked with just install && just lint-ci && just test-ci. Local runs are macOS/arm64; CI is the verdict on manylinux wheel coverage.