gh-35825: Fix tests for singular 4.3.2p2
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See:
https://github.com/sagemath/sage/issues/35676#issuecomment-1585711529
Both failures due to testing non-canonical output which gives different
results on singular 4.3.2p2 vs 4.3.2p1.
As mentioned in
https://github.com/sagemath/sage/issues/35676#issuecomment-1597921576,
printing `decomp` could be eliminated in both tests, since later on the
result is checked for correctness. However, they are documentation
examples and it might be useful for a user to see how the output looks
like.
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URL: https://github.com/sagemath/sage/pull/35825
Reported by: Gonzalo Tornaría
Reviewer(s):
