poppler_min: pin to poppler_0_61

poppler_min is only used by texlive.bin, which doesn't build
with poppler 0.64 and blocked the update poppler 0.63->0.64.
Pin to poppler_0_61 (which we currently need for libreoffice)
so we don't have to keep 0_63 as a third version.
See discussion in #40327 and #40180