Fixed typo in php version array

[danielmorell]

Description of the change

This fixes a typo in the main CI GitHub Action. Each PHP version in the array should be separated by a comma.

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Maintenance
• New release

Related issues

None

Checklists

Development

• Lint rules pass locally
• The code changed/added as part of this pull request has been covered with tests
• All tests related to the changed code pass in development

Code review

• This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached
• "Ready for review" label attached to the PR and reviewers assigned
• Issue from task tracker has a link to this pull request
• Changes have been reviewed by at least one other engineer

[danielmorell]

This build is going to fail because our dependency chain is not compatible with PHP 8. We need psr/log to be at least v2 or above. However, we are depending on rollbar/rollbar v2 which requires psr/log v1 and PHP 7.

I initially marked this as a draft after the build failed to verify there were not any other issues in our CI pipeline. However, now that I know we need to get our version of rollbar/rollbar to v3 to make this work I will create a separate branch/PR to contain the scope of that work.