federate job configuration does not seem to work

[Nishant Dash]

- When I configure this example federate job through the charm config `federate-config`,
```
- job_name: 'mesh-federate'
  scrape_interval: 2m
  scrape_timeout: 1m
  honor_labels: true
  metrics_path: '/federate'
  params:
    'match[]':
      - '{__name__=~".+"}'
  static_configs:
    - targets:
      - '<FQDN of other prometheus server>:9090'
```

- The job does not show up.
  In the Prometheus UI -> Status -> Configuration, I see
```
- job_name: mesh-federate
  honor_labels: true
  honor_timestamps: true
  params:
    match[]:
    - '{__name__=~".+"}'
  scrape_interval: 15s
  scrape_timeout: 15s
  metrics_path: /federate
  scheme: http
  follow_redirects: true
  enable_http2: true
  static_configs:
  - targets: []
    labels:
      group: promoagents-federate
```

As such, the target is missing and the scrape interval and timeout seem to be from the charm configs `scrape-timeout` and `scrape-interval` instead.

This charm is stable, 48.

[Nishant Dash (dash3)]

The jinja template does NOT grab scrape timeout and interval in the federate config section

```
# federate jobs
{%- if federate %}
{%- for job in federate %}
  - job_name: '{{ job['job_name'] }}'
    honor_labels: true
{%- if job.get('metrics_path') %}
    metrics_path: {{ job['metrics_path'] }}
{%- else %}
    metrics_path: /federate
{%- endif %}
{%- if job.get('scheme') %}
    scheme: {{ job['scheme'] }}
{%- endif %}
    params:
{%- for param, values in job['params'].items() %}
      '{{ param }}':
{%- for value in values %}
        - '{{ value }}'
{%- endfor %}
{%- endfor %}
    static_configs:
      - targets:
{%- for target in job['targets'] %}
          - {{ target }}
{%- endfor %}
        labels:
{%- if job.get('label') %}
          group: '{{job['label']}}'
{%- else %}
          group: 'promoagents-federate'
{%- endif %}
{%- endfor %}
{%- endif %}
```

[Nishant Dash (dash3)]

following the code, I see it outputs the template to `/var/snap/prometheus/current/prometheus.yml`
which has
```
# federate jobs
  - job_name: 'mesh-federate'
    honor_labels: true
    metrics_path: /federate
    params:
      'match[]':
        - '{__name__=~".+"}'
    static_configs:
      - targets:
        labels:
          group: 'promoagents-federate'

```

[Nishant Dash (dash3)]

I was able to see the job targets needed by changing the target snippet to
``` - targets:
{%- for item in job['static_configs'] %}
{%- for target in item['targets'] %}
          - {{ target }}
{%- endfor %}
{%- endfor %}
```