BUG: Fix memory leak in CRS.list_authority

[skogler]

List elements were not properly disposed of when iterating the results of proj_identify. This fixes this and simplifies the cleanup logic.

• Tests added (not sure how to test this automatically)
• Fully documented, including history.rst for all changes and api/*.rst for new API

You can reproduce this issue with the following snippet (look at the memory usage):

from pyproj import CRS

for i in range(10000):
    CRS.from_epsg(3857).to_epsg()

[snowman2]

Thanks @skogler 👍

[skogler]

Happy to help, thanks for the free software :)

[skogler]

@snowman2 I searched for other usages of proj_list_get and found one here: https://github.com/pyproj4/pyproj/blob/main/pyproj/_transformer.pyx#L204

What do you think about that one? It seems to me that https://github.com/pyproj4/pyproj/blob/main/pyproj/_transformer.pyx#L116 should probably call proj_destroy on all the child transformer objects?

[snowman2]

What do you think about that one?

I believe that should be fine. The _Transformer or CoordinateOperation object handles de-allocation of the objects.

[skogler]

Ah, I see, because Base is doing, it, you are right!

[snowman2]

Mind rebasing from main? I added a fix (#1179) that should allow the CICD tests to run to completion now.

[skogler]

Sure, done.

[codecov]

Codecov Report

Merging #1178 (07bf470) into main (07bf470) will not change coverage.
The diff coverage is n/a.

❗ Current head 07bf470 differs from pull request most recent head 01b793b. Consider uploading reports for the commit 01b793b to get more accurate results

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  Coverage   96.19%   96.19%           
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  Lines        1707     1707           
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  Hits         1642     1642           
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[snowman2]

Thanks @skogler 👍