fix: thread through workflow inputs to deprecation.js

[jcreedcmu]

Currently, deprecation.js calls core.getInput to get workflow inputs. But getInput expects these to come from the environment, and composite actions don't automatically populate their subprocesses' environments. Fix the workflow file so that all six options are threaded through, and also fix deprecation.js so that the default values of the non-deprecated options don't override the user's preference when they specify a deprecated option.

Makes progress on #13.

[jcreedcmu]

Manual testing

Here's what I did to test the effect on api_docs/api-docs.

1. [Defaults] In https://github.com/jcreedcmu/blueprint-debug/actions/runs/19395808751/job/55495645443
   see the workflow file has

      - name: Compile blueprint and documentation
        uses: jcreedcmu/docgen-action@main
        with:
          blueprint: false
          homepage: home_page

and in the action log we see

Compile blueprint and documentation →
/home/runner/work/_actions/jcreedcmu/docgen-action/main/scripts/build_docs.sh

(even though the docs build fails because we never built the project; that's because I
disabled project building for faster debugging iteration)

2. [Deprecated Option] In https://github.com/jcreedcmu/blueprint-debug/actions/runs/19395834934/job/55495704844
   see the workflow file has

      - name: Compile blueprint and documentation
        uses: jcreedcmu/docgen-action@main
        with:
          api_docs: false
          blueprint: false
          homepage: home_page

and in the action log we see

Compile blueprint and documentation →
Run node "/home/runner/work/_actions/jcreedcmu/docgen-action/main/dist/deprecation.js"
  node "/home/runner/work/_actions/jcreedcmu/docgen-action/main/dist/deprecation.js"
  shell: /usr/bin/bash --noprofile --norc -e -o pipefail {0}
  env:
    INPUT_API_DOCS: false
    INPUT_API-DOCS: true
    INPUT_BUILD_ARGS:
    INPUT_BUILD-ARGS: --log-level=warning
    INPUT_LAKE-PACKAGE-DIRECTORY: .
    INPUT_LAKE_PACKAGE_DIRECTORY:
Warning: The input parameter 'api_docs' is deprecated and will be removed in a future version. Please use 'api-docs' instead.
Run node "/home/runner/work/_actions/jcreedcmu/docgen-action/main/dist/index.js"
  node "/home/runner/work/_actions/jcreedcmu/docgen-action/main/dist/index.js"
  shell: /usr/bin/bash --noprofile --norc -e -o pipefail {0}
  env:
    LAKE_PACKAGE_DIRECTORY: .
    API_DOCS: false
    BUILD_ARGS: --log-level=warning

and we do not see
/home/runner/work/_actions/jcreedcmu/docgen-action/main/scripts/build_docs.sh, which is correct.

3. [Recommended Option] In https://github.com/jcreedcmu/blueprint-debug/actions/runs/19395868420/job/55495783966
   see the workflow file has

      - name: Compile blueprint and documentation
        uses: jcreedcmu/docgen-action@main
        with:
          api-docs: false
          blueprint: false
          homepage: home_page

and in the action log we see

Run node "/home/runner/work/_actions/jcreedcmu/docgen-action/main/dist/deprecation.js"
  node "/home/runner/work/_actions/jcreedcmu/docgen-action/main/dist/deprecation.js"
  shell: /usr/bin/bash --noprofile --norc -e -o pipefail {0}
  env:
    INPUT_API_DOCS:
    INPUT_API-DOCS: false
    INPUT_BUILD_ARGS:
    INPUT_BUILD-ARGS: --log-level=warning
    INPUT_LAKE-PACKAGE-DIRECTORY: .
    INPUT_LAKE_PACKAGE_DIRECTORY:
Run node "/home/runner/work/_actions/jcreedcmu/docgen-action/main/dist/index.js"
  node "/home/runner/work/_actions/jcreedcmu/docgen-action/main/dist/index.js"
  shell: /usr/bin/bash --noprofile --norc -e -o pipefail {0}
  env:
    LAKE_PACKAGE_DIRECTORY: .
    API_DOCS: false
    BUILD_ARGS: --log-level=warning

and we do not see
/home/runner/work/_actions/jcreedcmu/docgen-action/main/scripts/build_docs.sh, which is correct.