ENH: adding sys.version to User-Agent

[bsipocz]

Kind of a follow-up to #344

This potentially would help us to see when to drop python version support, etc.

The connecting astroquery PR is here: astropy/astroquery#2762

[codecov]

Codecov Report

Merging #452 (16b490c) into main (c4f67e5) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #452      +/-   ##
==========================================
- Coverage   80.08%   80.08%   -0.01%     
==========================================
  Files          52       52              
  Lines        6021     6020       -1     
==========================================
- Hits         4822     4821       -1     
  Misses       1199     1199              

Impacted Files	Coverage Δ
pyvo/utils/http.py	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

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[msdemlei]

As per RFC 7231 (or our VO digestion of it, https://ivoa.net/documents/Notes/softid/), this will make the python version and the OS a comment on pyVO. If that's what you want, I'll not stand in your way.

Me, I'd say the python system is a "product" in the sense of RFC 7231, and hence I'd slightly prefer having something like "pyVO/1.4 python/3.14 (linux)" as the UA string. Making the OS another product... ah, let's not overdo it.

[bsipocz]

Thanks for the approval. I have zero preference about the formatting, so I will change to your suggestion, it's less cryptic anyway than the current one.