Incompatible with pystac

[zxdawn]

Describe the bug

To search Carbon Mapper products using pystac, I need to set the method as GET manually. According to pystac's function guide, if the status is 405, the method should change from "POST" to "GET" automatically. I see the status returned from Carbon Mapper is 422. It would be nice to make pystac work for Carbon Mapper API by default.

To Reproduce
Steps to reproduce the behavior:

from pystac_client import Client
from shapely import Point

lat_center = 19.324569
lon_center = -98.804675

point = Point(lon_center, lat_center)
bbox = point.buffer(0.05).bounds

params = {
    "bbox": bbox,
    "collections": "l3a-ch4",
    # "method": 'GET',
    "method": 'POST',
}

api_url = "https://api.carbonmapper.org/api/v1/stac/"
cat = Client.open(api_url)

search = cat.search(**params)
items = search.item_collection()