Adjust Existing Host Provider

[pjhartzell]

Describe the bug
Since this is an open source project that should should not be aimed at one particular user, it might be best to remove Microsoft from the providers list (host role) and simply add the host role to the USGS provider. Per the STAC specification, there should be only one host provider.

To reproduce
See the providers list in the Collection examples.

Relevant portion of the landsat-c2-l1 example STAC Collection:

"providers": [
    {
      "name": "NASA",
      "roles": [
        "producer",
        "licensor"
      ],
      "url": "https://landsat.gsfc.nasa.gov/"
    },
    {
      "name": "USGS",
      "roles": [
        "producer",
        "processor",
        "licensor"
      ],
      "url": "https://www.usgs.gov/landsat-missions/landsat-collection-2-level-1-data"
    },
    {
      "name": "Microsoft",
      "roles": [
        "host"
      ],
      "url": "https://planetarycomputer.microsoft.com"
    }
  ],