TileDB-SOMA 1.15.7

The sole purpose of this release is to include #3671 which fixes an issue with the 1.15.6 release being incompatible with pyarrow versions below 17, as described by issue #3667.

Bugfixes

• [Backport release-1.15] [python] Resolve issue with #3611 and pyarrow<17 by @johnkerl in #3671

Misc.

• [r] TileDB-SOMA 1.15.7 by @johnkerl in #3670

Full Changelog: 1.15.6...1.15.7