Make `circularity_npv` example work again and re-enable regression test

[alexdewar]

Describe the bug

As of #1319, the circularity_npv patch example doesn't run to completion any more:

[10:45:48 INFO muse2::simulation] Milestone year: 2040
[10:45:48 INFO muse2::simulation] Running agent investment...
[10:45:48 WARN muse2::simulation::investment] Investment appraisal completed with unmet demand for commodity 'GASOLI', region 'GBR', year '2040', agent 'A0_REF'. 1 non-feasible investments were not considered. This unmet demand may still be satisfied during the full system dispatch.
[10:45:48 WARN muse2::simulation::investment] Investment appraisal completed with unmet demand for commodity 'BIOPEL', region 'GBR', year '2040', agent 'A0_BPL'. 1 non-feasible investments were not considered. This unmet demand may still be satisfied during the full system dispatch.
[10:45:48 ERROR muse2] Agent investment failed

Caused by:
    The solver has indicated that the problem is infeasible, probably because the supplied assets could not meet the required demand. Demand was not met for the following markets: [(CommodityID("TPASKM"), RegionID("GBR"))]

I'm disabling the regression test for now. But we should figure out why this model isn't working and re-enable the test.

To Reproduce

cargo run example run --patch circularity_npv

[alexdewar]

Other issues that may be related: #1201 and #1358