8.1.0_RC2 Release Prep (#5398)

* Update csm plugins path in IsisPreferences (#5397)

* Update csm plugins path in IsisPreferences

* Update changelog

* Add trailing slash

* 8.1.0_RC2 version ticks

* Moved changelog entry

* 8.1.0_RC2 Updates (#5399)

* 8.2.0_RC2 updates

* Changes for 8.1.0_RC2 (#5387)

* Fix dependency formatting in meta.yaml

* Pin gsl, update docs

* Revert pin

* Pin gsl to 2.6

* Add 8.1.0_RC1 as separate code entry

* Update the urls for 8.0 entry

* Turn on python bindings to be installed during build

* Add back kakadu build

* Add pybindings changelog entry

* Revert "Changes for 8.1.0_RC2 (#5387)"

This reverts commit 799445486bcff8368ade3f0096d5f23be3d0d57a.

* Bump ALE to 0.10.0

* Update csm plugins path from CONDA_PREFIX to ISISROOT

* Set build num to 0, add back rc1 code entry