Feature request: Add native uv support and configuration

  Upstream Issues in aws-lambda-builders UV Workflow

  All bugs are in the experimental PythonUvBuilder workflow (aws-lambda-builders, shipped with SAM CLI >= 1.155.2). The
   relevant code lives in aws_lambda_builders/workflows/python_uv/.

  Bug 1: Dev dependencies included in build artifact

  File: packager.py, _build_from_lock_file() ~line 326-338

  Problem: The uv export command is missing --no-dev. All dependencies from [dependency-groups] dev in pyproject.toml
  are exported and installed into the Lambda artifact.

  Impact: Build artifact balloons from ~144M to ~408M (in our case), including pytest, pyright, cfn-lint, coverage,
  etc. Exceeds Lambda's 250MB unzipped size limit.

  Expected: uv export should include --no-dev to exclude development dependencies from production builds.

  Current code:
  export_args = [
      "export",
      "--format", "requirements.txt",
      "--no-emit-project",
      "--no-hashes",
      "--output-file", temp_requirements,
      "--python", python_version,
  ]

  Fix: Add "--no-dev" to export_args.

  ---
  Bug 2: --cached mode fails with CopyDependenciesAction

  File: workflow.py, _setup_build_actions() ~line 142-151

  Problem: When --cached is used (i.e. dependencies_dir is set), deps are installed to .aws-sam/deps/<uuid>/ but the
  CopyDependenciesAction is constructed with swapped semantics. It tries to os.listdir(artifact_dir)
  (.aws-sam/build/ExampleFunction) which doesn't exist yet — the deps are in destination_dir (.aws-sam/deps/).

  Error: [Errno 2] No such file or directory: '.aws-sam/build/ExampleFunction'

  Current code:
  CopyDependenciesAction(
      source_dir=source_dir,
      artifact_dir=artifacts_dir,          # .aws-sam/build/ExampleFunction (empty)
      destination_dir=self.dependencies_dir, # .aws-sam/deps/... (has deps)
  )

  The DependencyManager.yield_source_dest() does os.listdir(self._artifact_dir) then copies FROM artifact_dir TO
  dest_dir — which is backwards. Deps are in dependencies_dir but it tries to read from artifacts_dir.

  Impact: Every sam build with --cached fails for the UV workflow. Without --cached, builds always re-download deps.

  ---
  Bug 3: [tool.uv.pip] config leaks into builder subprocess

  File: packager.py, _build_from_lock_file() ~line 345-353

  Problem: The uv pip install command runs with cwd=project_dir, which makes uv read [tool.uv.pip] settings from the
  project's pyproject.toml. If the project has require-hashes = true (common security practice), but the builder
  exported with --no-hashes, uv pip install fails because it requires hashes that aren't present.

  Error: error: In --require-hashes mode, all requirements must have a hash, but none were provided for: aenum==3.1.16

  Root cause: The builder explicitly exports with --no-hashes (line 331) but doesn't account for the project's
  [tool.uv.pip] config overriding the install behavior. The uv pip install inherits the project's pyproject.toml
  settings since it runs from the project directory.

  Possible fixes:
  - Pass --no-verify-hashes to the uv pip install command
  - Run uv pip install with UV_NO_VERIFY_HASHES=true in the subprocess env
  - Export WITH hashes instead of --no-hashes (then the require-hashes config is satisfied)
  - Run uv pip install from a temp dir without pyproject.toml context

  ---
  Our Workarounds

  ┌────────────────────────┬───────────────────────────────────────────────────────────────────────────┐
  │          Bug           │                                Workaround                                 │
  ├────────────────────────┼───────────────────────────────────────────────────────────────────────────┤
  │ Bug 1 (dev deps)       │ Generate our own uv export --no-dev requirements file, pass as --manifest │
  ├────────────────────────┼───────────────────────────────────────────────────────────────────────────┤
  │ Bug 2 (--cached)       │ Don't use --cached flag                                                   │
  ├────────────────────────┼───────────────────────────────────────────────────────────────────────────┤
  │ Bug 3 (require-hashes) │ Removed generate-hashes/require-hashes from pyproject.toml [tool.uv.pip]  │
  └────────────────────────┴───────────────────────────────────────────────────────────────────────────┘

  Bugs 1 and 2 are worked around by the same mechanism: since we generate our own requirements-*.txt via uv export
  --no-dev --no-hashes --frozen --no-emit-project, the lambda-builders use the _build_from_requirements path (simple uv
   pip install -r) instead of the buggy _build_from_lock_file path. This also avoids the --cached
  CopyDependenciesAction issue since we don't use --cached.