Flaky `tests/tensor/signal/test_conv.py::test_batched_1d_agrees_with_2d_row_filter[fft-full]`

[ricardoV94]

Description

Saw it fail a couple of times, last time here: https://github.com/pymc-devs/pytensor/actions/runs/20210337085/job/58016685728?pr=1778#step:6:5360