VLN-1393: remediate missing-dependency-cooldown

[picatz]

🏕️ This pull request was created by camper, an automated security campaign tool.

Finding

Rule	missing-dependency-cooldown
Severity	MEDIUM
Repository	temporalio/samples-php
Ticket	VLN-1393

Summary

• .github/dependabot.yml: Added a new Dependabot configuration with weekly schedules and cooldown.default-days: 14 for both the composer ecosystem (/app) and github-actions (/).

Instructions

• Approve to merge this fix
• Request changes to trigger a new remediation attempt
• /camper rebase — rebase onto the base branch
• /camper close — close this PR without merging
• /camper retry — close and retry with a new fix

[picatz]

This PR has had no activity for 7 days and may need attention.

Actions you can take:

• Review and approve if the changes look good
• Close if this fix is no longer needed
• Comment /camper rebase to rebase onto the latest base branch
• Comment /camper retry to regenerate the fix

[picatz]

This PR has had no activity for 9 days and may need attention.

Actions you can take:

• Review and approve if the changes look good
• Close if this fix is no longer needed
• Comment /camper rebase to rebase onto the latest base branch
• Comment /camper retry to regenerate the fix