Support for setting environment variables in cloudflared Deployment

Hi team,

Thank you for maintaining this chart.

I'd like to request support for specifying environment variables in the cloudflared Deployment. Currently, there is no .Values.env section or similar mechanism to inject custom environment variables into the container.

Cloudflare's cloudflared supports a variety of configuration parameters via environment variables, as documented here:
📘 https://developers.cloudflare.com/cloudflare-one/connections/connect-networks/configure-tunnels/cloudflared-parameters/run-parameters/

Being able to set variables such as TUNNEL_TOKEN, NO_AUTOUPDATE, or TUNNEL_METRICS directly in the Helm values would be very helpful for flexibility and automation.

Proposed change:

Add support for an env section in the values file.

Update the deployment template to render it under containers.env.

Example values.yaml:

```yaml
env:
- name: TUNNEL_LOGLEVEL
value: "info"
- name: NO_AUTOUPDATE
value: "true"
```
I’d be happy to contribute a PR for this enhancement if the maintainers agree this would be a valuable addition.

Thanks!