Automate `zilla` `develop-SNAPSHOT` acceptance tests for `zilla-examples` scenarios

[vordimous]

Describe the desired outcome from the user's perspective
As a zilla developer, I want to have confidence that my changes have no negative impact on zilla-examples scenarios.

Acceptance criteria

• Each zilla-examples scenario is automated via GitHub Actions, following the steps in each README
• The develop-SNAPSHOT version of zilla is used for automated testing by default
• A local develop-SNAPSHOT build of zilla is created and cached via GitHub Actions as needed
• If any of the steps in the README do not behave as expected, then the GitHub Actions workflow fails
• Enough information is retained when the GitHub Actions workflow fails to diagnose the failure
• Ideally, the same tools recommended by the README are used by the workflow to verify correctness
• The workflow may be triggered by a timer, or manually

Additional context
See potentially helpful kind tool for k8s automation.

Running GH actions can be executed in a container. The container needed for the GH action can be pulled locally to test any action steps.

sparse-checkout can only clone certain folders or patterns of folders.

Export results to the $GITHUB_OUTPUT var.

Use path-specific action triggers and global env vars to make jobs and tasks more generic.

on:
  push:
    paths:
      - "path/to/example/**/*"

env:
  EXAMPLE_PATH: path/to/example

Tasks

• Add a GH action to build the head of develop and run example tests #1263
• automate amqp.reflect
• automate asyncapi.http.kafka.proxy
• automate asyncapi.mqtt.kafka.proxy
• automate asyncapi.mqtt.proxy
• automate asyncapi.sse.kafka.proxy
• automate asyncapi.sse.proxy
• automate grpc.echo
• automate grpc.kafka.echo
• automate grpc.kafka.fanout
• automate grpc.kafka.proxy
• automate grpc.proxy
• automate http.filesystem
• automate http.json.schema
• automate http.kafka.async
• automate http.kafka.cache
• automate http.kafka.crud
• automate http.kafka.oneway
• automate http.kafka.proto.json
• automate http.kafka.proto.oneway
• automate http.kafka.sync
• automate http.proxy
• automate http.proxy.jwt
• automate mqtt.kafka.proxy
• automate mqtt.proxy.jwt
• automate openapi.asyncapi.kakfa.proxy
• automate openapi.proxy
• Automate openapi.proxy scenario acceptance tests zilla-examples#124
• automate sse.kafka.fanout
• automate sse.proxy.jwt
• automate tcp.echo
• automate tcp.reflect
• Automate tls.echo scenario acceptance tests zilla-examples#125
• automate tls.reflect
• automate ws.echo
• automate ws.reflect