Drop python 3.8 support & napari backends

[paddyroddy]

NEP29 https://numpy.org/neps/nep-0029-deprecation_policy.html

[codecov-commenter]

Codecov Report

Patch coverage: 100.00% and project coverage change: -0.01 :warning:

Comparison is base (93d18e7) 85.64% compared to head (e145b56) 85.63%.

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Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #325 +/- ## ========================================== - Coverage 85.64% 85.63% -0.01% ========================================== Files 30 30 Lines 1957 1956 -1 Branches 296 296 ========================================== - Hits 1676 1675 -1 Misses 201 201 Partials 80 80 ``` | [Impacted Files](https://app.codecov.io/gh/quantumjot/btrack/pull/325?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe) | Coverage Δ | | |---|---|---| | [btrack/btypes.py](https://app.codecov.io/gh/quantumjot/btrack/pull/325?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe#diff-YnRyYWNrL2J0eXBlcy5weQ==) | `82.54% <100.00%> (ø)` | | | [btrack/config.py](https://app.codecov.io/gh/quantumjot/btrack/pull/325?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe#diff-YnRyYWNrL2NvbmZpZy5weQ==) | `96.87% <100.00%> (ø)` | | | [btrack/core.py](https://app.codecov.io/gh/quantumjot/btrack/pull/325?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe#diff-YnRyYWNrL2NvcmUucHk=) | `84.00% <100.00%> (ø)` | | | [btrack/datasets.py](https://app.codecov.io/gh/quantumjot/btrack/pull/325?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe#diff-YnRyYWNrL2RhdGFzZXRzLnB5) | `84.84% <100.00%> (-0.45%)` | :arrow_down: | | [btrack/io/\_localization.py](https://app.codecov.io/gh/quantumjot/btrack/pull/325?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe#diff-YnRyYWNrL2lvL19sb2NhbGl6YXRpb24ucHk=) | `91.96% <100.00%> (+0.07%)` | :arrow_up: | | [btrack/io/hdf.py](https://app.codecov.io/gh/quantumjot/btrack/pull/325?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe#diff-YnRyYWNrL2lvL2hkZi5weQ==) | `78.54% <100.00%> (ø)` | | | [btrack/io/importers.py](https://app.codecov.io/gh/quantumjot/btrack/pull/325?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe#diff-YnRyYWNrL2lvL2ltcG9ydGVycy5weQ==) | `100.00% <100.00%> (ø)` | | | [btrack/io/utils.py](https://app.codecov.io/gh/quantumjot/btrack/pull/325?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe#diff-YnRyYWNrL2lvL3V0aWxzLnB5) | `88.37% <100.00%> (ø)` | | | [btrack/models.py](https://app.codecov.io/gh/quantumjot/btrack/pull/325?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe#diff-YnRyYWNrL21vZGVscy5weQ==) | `89.76% <100.00%> (ø)` | | | [btrack/napari/reader.py](https://app.codecov.io/gh/quantumjot/btrack/pull/325?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe#diff-YnRyYWNrL25hcGFyaS9yZWFkZXIucHk=) | `73.33% <100.00%> (+0.91%)` | :arrow_up: | | ... and [2 more](https://app.codecov.io/gh/quantumjot/btrack/pull/325?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe) | |

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[deprecated-napari-hub-preview-bot[bot]]

Preview page for your plugin is ready here: https://preview.napari-hub.org/quantumjot/btrack/325 Created: 2023-05-25T15:15:59.712211

[paddyroddy]

I need this merged for what I'm doing