fix(dgw): honor TCP_PORT in Linux container entrypoint

[Dahllias]

Fixes an issue where the TCP_PORT environment variable was ignored by the Docker Gateway.
Even when TCP_PORT was set, the gateway continued to use the default TCP port.
This change ensures the gateway now correctly applies the configured TCP_PORT value at startup.

[github-actions]

Let maintainers know that an action is required on their side

• Add the label release-required Please cut a new release (Devolutions Gateway, Devolutions Agent, Jetsocat, PowerShell module) when you request a maintainer to cut a new release (Devolutions Gateway, Devolutions Agent, Jetsocat, PowerShell module)

• Add the label release-blocker Follow-up is required before cutting a new release if a follow-up is required before cutting a new release

• Add the label publish-required Please publish libraries (`Devolutions.Gateway.Utils`, OpenAPI clients, etc) when you request a maintainer to publish libraries (Devolutions.Gateway.Utils, OpenAPI clients, etc.)

• Add the label publish-blocker Follow-up is required before publishing libraries if a follow-up is required before publishing libraries

[CBenoit]

LGTM!