updating this workflow so that it can be called remotely

[sean-sype-simmons]

this workflow was being pointed to via the .github/workflows/ci-main-pull-request-checks.yml file, which also points to .github/workflows/trufflehog.yml

just updated this workflow to be allowed to work on workflow_call

error sourced from: https://github.com/chef/omnibus-harmony/actions/runs/13510869981 https://github.com/chef/omnibus-harmony/pull/147

[Invalid workflow file: .github/workflows/ci-main-pull-request-checks.yml#L16](https://github.com/chef/omnibus-harmony/actions/runs/13510869981/workflow)
error parsing called workflow
".github/workflows/ci-main-pull-request-checks.yml"
-> "chef/common-github-actions/.github/workflows/ci-main-pull-request-checks.yml@main" (source branch with sha:c42cbbf897f7e13eecf6d3ac17733ab1e3c5ebd3)
--> "chef/common-github-actions/.github/workflows/trufflehog.yml@main" (source branch with sha:c42cbbf897f7e13eecf6d3ac17733ab1e3c5ebd3)
: workflow is not reusable as it is missing a `on.workflow_call` trigger

Description

Related Issue

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Chore (non-breaking change that does not add functionality or fix an issue)

Checklist:

• I have read the CONTRIBUTING document.
• I have run the pre-merge tests locally and they pass.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• If Gemfile.lock has changed, I have used --conservative to do it and included the full output in the Description above.
• All new and existing tests passed.
• All commits have been signed-off for the Developer Certificate of Origin.