Temporarily pin camb<2 and scipy<1.18

[heather999]

Following this thread on Slack and the cosmosis installation instructions which currently provides a modified install step when using camb >- 2.0 or scipy 1.18. Currently the new td_env includes both. The long term fix seems to rely on an jablazek/FAST-PT#25. The short term fix is either to restrict the environment to camb < 2 and scipy 1.17 or use a patched version of fast-pt:

conda uninstall --force fast-pt
pip install "git+https://github.com/joezuntz/FAST-PT/"