docs: fix typo Update deployment-gcp.md

[mdqst]

This update adjusts the wording in the GCP deployment guide to align with formal technical documentation standards. Specifically, the phrase:

"Some gcloud commands might not run in an ephemeral Cloud Shell environment."

has been refined to:

"Some gcloud commands may not run in an ephemeral Cloud Shell environment."

The change from "might" to "may" reflects a more formal tone, consistent with the style of the guide.