Audacity can find the silences and label them … Silence Finder - Setting Parameters - Audacity Manual
That would split up your recording into many tracks which you could export (multiple) into a folder.
Then sort those many files in the folder according to size, biggest will be the longest.
That will sort the long from the short sections of audio, but you will lose chronological order.
I think it would be possible using Nyquist code to remove labelled sections shorter than a given interval,
(preserving chronology), but that’s over my head. [ Steve is the man for that job ]
[ BTW Audacity cannot identify “conversation” : it’s just splitting the audio into intervals separated by silence ].