fix: Change build-image CLI argument to files

[liamcoatman]

Issue #, if available:

Description of changes:

Change argument name from file to files, which is what is read on lines 56 and 58. I've tested this manually and verified that only machine image foo is built when I run pnpx sls build-image --files foo.json -s dev.

Checklist:

• Have you successfully deployed to an AWS account with your changes?
• Have you written new tests for your core changes, as applicable?
• Have you successfully tested with your changes locally?
• If new dependencies have been added, have they been pinned to specific versions?
• Is this change also required on the AWS Solution version?
• Have you updated openapi.yaml if you made updates to API definition (including add, delete or update parameter and request data schema)?
• If you had to run manual tests, have you considered automating those tests by adding them to end-to-end tests?
• If you are updating the changelog and vending out a new release, have you updated versionNumber and versionDate in .defaults.yml

AS review ticket id:

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[SanketD92]

Could you provide more details as to what didn't work earlier with the "file" argument?

[codecov]

Codecov Report

Merging #825 (ef2e351) into develop (772617f) will not change coverage.
The diff coverage is n/a.

❗ Current head ef2e351 differs from pull request most recent head 43bb068. Consider uploading reports for the commit 43bb068 to get more accurate results

@@           Coverage Diff            @@
##           develop     #825   +/-   ##
========================================
  Coverage    50.91%   50.91%           
========================================
  Files          286      286           
  Lines        15931    15931           
  Branches      2485     2485           
========================================
  Hits          8111     8111           
  Misses        6863     6863           
  Partials       957      957           

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[liamcoatman]

Could you provide more details as to what didn't work earlier with the "file" argument?

As far as I could tell it it does nothing. An argument like --file foo.json is ignored and the default (to build all Packer files in the directory) is used instead.

[SanketD92]

Could you provide more details as to what didn't work earlier with the "file" argument?

As far as I could tell it it does nothing. An argument like --file foo.json is ignored and the default (to build all Packer files in the directory) is used instead.

Was able to verify the --files flag was honored while the --flag flag wasn't.

Please pull the latest changes from develop by clicking on the "Update branch" button below. Also, please add a commit (could even be an empty one) that starts with a conventional commit type.