`:py:func:` links fixed

Co-Authored-By: keewis <keewis@users.noreply.github.com>

…o-combine

* 'master' of github.com:pydata/xarray: (81 commits)
  use builtin python types instead of the numpy alias (pydata#4170)
  Revise pull request template (pydata#4039)
  pint support for Dataset (pydata#3975)
  drop eccodes in docs (pydata#4162)
  Update issue templates inspired/based on dask (pydata#4154)
  Fix failing upstream-dev build & remove docs build (pydata#4160)
  Improve typehints of xr.Dataset.__getitem__ (pydata#4144)
  provide a error summary for assert_allclose (pydata#3847)
  built-in accessor documentation (pydata#3988)
  Recommend installing cftime when time decoding fails. (pydata#4134)
  parameter documentation for DataArray.sel (pydata#4150)
  speed up map_blocks (pydata#4149)
  Remove outdated note from datetime accessor docstring (pydata#4148)
  Fix the upstream-dev pandas build failure (pydata#4138)
  map_blocks: Allow passing dask-backed objects in args (pydata#3818)
  keep attrs in reset_index (pydata#4103)
  Fix open_rasterio() for WarpedVRT with specified src_crs (pydata#4104)
  Allow non-unique and non-monotonic coordinates in get_clean_interp_index and polyfit (pydata#4099)
  update numpy's intersphinx url (pydata#4117)
  xr.infer_freq (pydata#4033)
  ...