Remove deprecated API

[dstansby]

Fixes https://github.com/zarr-developers/zarr-python/issues/3317. I'm going to leave this as draft, because it will probably be easier to manage backports if this is merged as the last thing before a 3.2.0 release, in case any of the removed API needs fixing in 3.1.x. Opening to avoid duplicaiton of work by others.

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 62.22%. Comparing base (7d8105f) to head (b7c443e).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3325      +/-   ##
==========================================
+ Coverage   61.95%   62.22%   +0.26%     
==========================================
  Files          86       84       -2     
  Lines       10170    10086      -84     
==========================================
- Hits         6301     6276      -25     
+ Misses       3869     3810      -59     

Files with missing lines	Coverage Δ
src/zarr/__init__.py	64.44% <ø> (ø)
src/zarr/api/asynchronous.py	73.11% <100.00%> (+0.91%)	:arrow_up:
src/zarr/api/synchronous.py	37.87% <100.00%> (+1.25%)	:arrow_up:
src/zarr/core/array.py	69.55% <ø> (+1.06%)	:arrow_up:
src/zarr/core/common.py	47.20% <ø> (ø)
src/zarr/core/group.py	70.96% <ø> (+0.69%)	:arrow_up:
src/zarr/storage/__init__.py	0.00% <ø> (-10.00%)	:arrow_down:

:rocket: New features to boost your workflow:

• :snowflake: Test Analytics: Detect flaky tests, report on failures, and find test suite problems.