Migrate to Boost 1.78

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-webservice.

I've rerendered the recipe as instructed in #71.

Here's a checklist to do before merging.

• [x] Bump the build number if needed.

Fixes #71

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[jakirkham]

@conda-forge-admin, please re-render

[jakirkham]

@conda-forge/casacore, please review 🙂