Try PETSc bisect3 branch

Author: connorjward

.github/workflows/build.yml

@@ -88,7 +88,7 @@ jobs:
             --install defcon \
             --install gadopt \
             --install asQ \
-            --package-branch petsc connorjward/bisect2 \
+            --package-branch petsc connorjward/bisect3 \
             --package-branch slepc connorjward/merge-upstream \
             || (cat firedrake-install.log && /bin/false)