Disable ci-fuzz build on build branch
Disable ci-fuzz build on build branch

I run the fuzzer test suite, which should be good enough to avoid
wasting resources on this every time I push to build.

jberkenbilt/qpdf,qpdf/qpdf,qpdf/qpdf,jberkenbilt/qpdf,qpdf/qpdf,jberkenbilt/qpdf,jberkenbilt/qpdf,jberkenbilt/qpdf,qpdf/qpdf,qpdf/qpdf