Allow to use of system blosc2 to build pytables

[avalentino]

Closes #986.
Closes #984.

[mgorny]

Thanks. It seems to work fine for us. LGTM modulo the typo (but I don't know about Conda).

[avalentino]

Thanks @mgorny

[FrancescAlted]

Looks good to me. In the future, I'd like to strictly require python-blosc2 for allowing the registration of user-defined codecs and filters straight from Python, and hence, accessible from PyTables. But that will be next year, the soonest ;-)

[avalentino]

Thanks @FrancescAlted.
Probably switching to a build system based on cmake or meson would help a lot in our case.
This is something that I had in mind singe very long time, probably it is time to start thinking to it more seriously.

Do you have experience with scikit-build or meson? ... or any other alternative?

[mgorny]

My experience with scikit-build is one of pure horror and revulsion, please don't do that. meson on the other hand can be quite good, especially with meson-python PEP517 backend. There are some rough edges, particularly regarding installing pkg-config files and other data that doesn't fit cleanly inside a venv but I don't think any of that applies to PyTables.

[avalentino]

@mgorny do you know other alternatives it that could worth to consider?

[mgorny]

I could joke autotools but you probably don't want to do that ;-). No, I think meson is the state of art right now, as far as build systems are concerned, and it's getting first-class support from a lot of people right now, so if you hit any problems there's a good chance someone will provide a good solution.