Thanks for the hint. The current versions of libgnutls indeed reside in /usr/lib/x86_64-linux-gnu/libgnutls.so.30 and /usr/lib/i386-linux-gnu/libgnutls.so.30. After removing the spurious /usr/lib/libgnutls.so.30 and /usr/local/lib/libgnutls.so.30 which seem to have resided there since 2018 it works flawlessly again.
Thanks for the hint. The current versions of libgnutls indeed reside in /usr/lib/ x86_64- linux-gnu/ libgnutls. so.30 and /usr/lib/ i386-linux- gnu/libgnutls. so.30. After removing the spurious /usr/lib/ libgnutls. so.30 and /usr/local/ lib/libgnutls. so.30 which seem to have resided there since 2018 it works flawlessly again.