Remove labels on scraped Origins/Caches

[CannonLock]

Remove some of the metadata that currently is attached to metrics for scraped Origins and Caches.

• instance
• job
• server_auth_url
• server_lat
• server_long
• server_url
• server_web_url

All of these are subject to change and when they do they create discontinuity in the time series which makes them harder to query.
I can get all this information via the api if needed, and since they are not interesting to filter they aren't used anyways.

For instance when I query process_start_time_seconds[1w] it gives me two time series for the same server because the Geo code got tweaked.

      {
        "metric": {
          "__name__": "process_start_time_seconds",
          "instance": "unl-cache.nationalresearchplatform.org:1094",
          "job": "origin_cache_servers",
          "server_auth_url": "https://unl-cache.nationalresearchplatform.org:8443",
          "server_lat": "40.8035",
          "server_long": "-96.6510",
          "server_name": "NEBRASKA_NRP_OSDF_CACHE",
          "server_type": "Cache",
          "server_url": "https://unl-cache.nationalresearchplatform.org:8443",
          "server_web_url": "https://unl-cache.nationalresearchplatform.org:1094"
        },
      },
      {
        "metric": {
          "__name__": "process_start_time_seconds",
          "instance": "unl-cache.nationalresearchplatform.org:1094",
          "job": "origin_cache_servers",
          "server_auth_url": "https://unl-cache.nationalresearchplatform.org:8443",
          "server_lat": "40.8161",
          "server_long": "-96.7036",
          "server_name": "NEBRASKA_NRP_OSDF_CACHE",
          "server_type": "Cache",
          "server_url": "https://unl-cache.nationalresearchplatform.org:8443",
          "server_web_url": "https://unl-cache.nationalresearchplatform.org:1094"
        },

[CannonLock]

@patrickbrophy There might be a way that I can write the query better to remove these so that the timeseries get munged together.

I will poke at the a bit more before adding a milestone.