Fix python 3.13 support. (#866)

Python 3.13 dropped module `cgi`, which was made available as a
stand-alone library named `legacy-cgi`. A recent bump in `litellm`
added it as a dependency, breaking their support for python 3.13.

This change adds the stand-alone version of `cgi` library.

Source https://docs.python.org/3/library/cgi.html

Author: blkt

poetry.lock

@@ -31,6 +31,7 @@ pygments = "==2.19.1"
 sqlite-vec-sl-tmp = "==0.0.4"
 greenlet = "==3.1.1"
 cachetools = "==5.5.1"
+legacy-cgi = "==2.6.2"
 
 presidio = "^0.1.0"
 presidio-analyzer = "^2.2.357"