Commit message for put step should include act_external_url

[danger-ranger]

When pooled resources are shared between different concourse installations it would be really helpful to have the atc_external_url metadata field in the commit message when an environment is claimed.

[concourse-bot]

Hi there!

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The current status is as follows:

• #119103333 Commit message for put step should include act_external_url

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