Filter https service discovery variables.

[mitchdenny]

Fixes: #8332

This PR adds a hack in to filter out emission of https service discovery variables in Docker Compose. This is because we don't yet do anything around configuring TLS with Docker Compose either in terms of having a certificate file injected into the container or setting up some kind of proxy.

As a result, the webfrontend in the default template can't talk to the API because it preferences HTTPS because the variable is there.

[Copilot]

Pull Request Overview

This pull request addresses the issue of inadvertently exposing HTTPS service discovery variables in Docker Compose, which prevents the webfrontend from connecting to the API due to its preference for HTTPS.

• Added a helper method to filter out HTTPS service discovery variables from the environment variables.
• Updated Docker Compose configuration to remove the problematic HTTPS variable entry.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/Aspire.Hosting.Docker/DockerComposePublishingContext.cs	Introduces the RemoveHttpsServiceDiscoveryVariables method to filter out HTTPS variables.
playground/publishers/Publishers.AppHost/docker-compose.yaml	Removes the HTTPS service discovery variable to align with the updated filtering logic.

Comments suppressed due to low confidence (2)

src/Aspire.Hosting.Docker/DockerComposePublishingContext.cs:341

• [nitpick] Consider extracting the 'services__' prefix into a named constant to improve clarity and maintainability.

kvp.Key.StartsWith("services__")

src/Aspire.Hosting.Docker/DockerComposePublishingContext.cs:335

• Add unit tests for RemoveHttpsServiceDiscoveryVariables to verify that HTTPS service discovery variables are correctly removed.

private static void RemoveHttpsServiceDiscoveryVariables(Dictionary<string, object> environmentVariables)