Fix BGV ring dimension underestimation with NOISE_FLOODING_MULTIPARTY + HYBRID on 128-bit builds

[dsuponitskiy]

src/pke/examples/threshold-fhe.cpp throws an exception:
E RuntimeError: /home/ubuntu/actions-runners/openfhe-python/_work/openfhe-python/openfhe-python/openfhe-python-packager/build/openfhe-development/src/pke/lib/scheme/bgvrns/bgvrns-parametergeneration.cpp:l.644:ParamsGenBGVRNSInternal(): The ring dimension found using estimated logQ(P) [16384] does does not meet security requirements. Report this problem to OpenFHE developers and set the ring dimension manually to 32768.