[sentinel-2]: Retry on urllib exception

[TomAugspurger]

Observed an error:

[INFO] 2023-10-03 20:02:10,671 -  === PCTasks: Task Failed! ===
[ERROR] 2023-10-03 20:02:10,671 - Failed to create item from blob://sentinel2l2a01/sentinel2-l2/14/R/LS/2022/01/27/S2A_MSIL2A_20220127T172601_N0400_R012_T14RLS_20220212T210659.SAFE/
Traceback (most recent call last):
  File "/opt/conda/lib/python3.8/site-packages/pystac/stac_io.py", line 300, in read_text_from_href
    with urlopen(req) as f:
  File "/opt/conda/lib/python3.8/urllib/request.py", line 222, in urlopen
    return opener.open(url, data, timeout)
  File "/opt/conda/lib/python3.8/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/opt/conda/lib/python3.8/urllib/request.py", line 640, in http_response
    response = self.parent.error(
  File "/opt/conda/lib/python3.8/urllib/request.py", line 569, in error
    return self._call_chain(*args)
  File "/opt/conda/lib/python3.8/urllib/request.py", line 502, in _call_chain
    result = func(*args)
  File "/opt/conda/lib/python3.8/urllib/request.py", line 649, in http_error_default
    raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 503: Operations per second is over the account limit.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/opt/conda/lib/python3.8/site-packages/pctasks/dataset/items/task.py", line 211, in create_items
    result = self._create_item(asset_uri, storage_factory)
  File "/mnt/batch/tasks/workitems/sentinel-2-process-chunk-09f7d19-cc-8752-599c767e2a06-tsk_gen_bl/job-1/create-items-12/wd/_code/sentinel2.py", line 95, in create_item
    item = with_backoff(
  File "/opt/conda/lib/python3.8/site-packages/pctasks/core/utils/backoff.py", line 149, in with_backoff
    return fn()
  File "/mnt/batch/tasks/workitems/sentinel-2-process-chunk-09f7d19-cc-8752-599c767e2a06-tsk_gen_bl/job-1/create-items-12/wd/_code/sentinel2.py", line 87, in get_item
    item: pystac.Item = stac.create_item(
  File "/opt/conda/lib/python3.8/site-packages/stactools/sentinel2/stac.py", line 57, in create_item
    granule_metadata = GranuleMetadata(safe_manifest.granule_metadata_href,
  File "/opt/conda/lib/python3.8/site-packages/stactools/sentinel2/granule_metadata.py", line 22, in __init__
    self._root = XmlElement.from_file(href, read_href_modifier)
  File "/opt/conda/lib/python3.8/site-packages/stactools/core/io/xml.py", line 74, in from_file
    text = read_text(href, read_href_modifier)
  File "/opt/conda/lib/python3.8/site-packages/stactools/core/io/__init__.py", line 20, in read_text
    return StacIO.default().read_text(read_href_modifier(href))
  File "/opt/conda/lib/python3.8/site-packages/pystac/stac_io.py", line 282, in read_text
    return self.read_text_from_href(href)
  File "/opt/conda/lib/python3.8/site-packages/pystac/stac_io.py", line 303, in read_text_from_href
    raise Exception("Could not read uri {}".format(href)) from e
Exception: Could not read uri https://sentinel2l2a01.blob.core.windows.net/senti..