chore(deps): bump uv to 0.10.12

[baszalmstra]

Stacked on #6037 + #6050. Continues the uv bump loop with one commit per upstream tag from 0.9.11 through 0.10.12. Stops at 0.10.12 because uv 0.11.0 ships astral-reqwest-middleware = "0.5.1" and reqwest = "0.13.x", which trip the Middleware trait identity vs. rattler/rattler-build's 0.4.2 + reqwest 0.12.x. Same wall the 0.9.10 PR coordinated around at the previous version line. Unblocking 0.11.0+ requires another coordinated cross-repo bump.

Each commit is pushed individually so CI runs per tag. Title will track the latest tag in this PR; the diff will collapse once #6037 and #6050 land.

API-compat notes per tag

The full per-tag log (with file paths and rationale) is in the working notes. Highlights:

• 0.9.15 — uv_git_types::GitUrl::from_fields gained a 4th lfs: GitLfs parameter; VcsInfo gained git_lfs: Option<bool>; RequirementsTxt::parse lost its &BaseClientBuilder arg.
• 0.9.16 — Tags::from_env gained a 7th is_cross: bool parameter; uv_auth::store_credentials_from_url moved to a method on BaseClient::credentials_cache(); BuildContext::direct_build gained a sources: SourceStrategy arg.
• 0.9.17 — uv_resolver::ExcludeNewerTimestamp renamed to ExcludeNewerValue.
• 0.9.18-0.9.30 — no code changes; flaky ROS network tests forced cranking nextest --retries to 8.
• 0.9.26 — uv_configuration::SourceStrategy removed; replaced by NoSources with inverted semantics. Trait sigs in uv_types::BuildContext flipped (fn sources(&self) -> &NoSources, fn setup_build(... sources: &'a NoSources, ...), fn direct_build(... sources: NoSources, ...)). Renamed UvResolutionContext::source_strategy → no_sources, with_source_strategy → with_no_sources. NoSources is not Copy, so a few cross-call moves became .clone()s (cheap, just Arcs underneath).
• 0.10.0 — BaseClientBuilder::timeout renamed to read_timeout. Most other 0.10.0 breakage already absorbed in the 0.9 patch line.
• 0.10.7 — Concurrency gained downloads_semaphore/builds_semaphore (Arc<Semaphore>); DistributionDatabase::new's 3rd arg flipped from usize to Arc<Semaphore>. Concurrency no longer Copy. Updated 4 call sites + threaded lock_pypi_packages's parameter.
• 0.10.9 — PyProjectToml::from_toml gained a _source: impl Display arg.

Excluded from the gate

tests/integration_python/pixi_build/test_build.py::test_extra_args is still skipped via -k 'not test_extra_args'. Same pre-existing meson _setup_vsenv issue documented on #6037 / #6050.

Test plan

For each commit, locally on Windows:

• cargo build --workspace --all-targets
• cargo nextest run --workspace --all-targets --features slow_integration_tests,online_tests --retries=8 --no-fail-fast — 1776 passed for every tag.
• cargo clippy --all-targets --workspace -- -D warnings
• cargo fmt --all -- --check

CI gates per-commit are pending; this PR is being pushed one commit at a time so that each tag lands in the CI history individually.