webviz-ert crashes on startup if you try to use any ert-internal forward models

[larsevj]

What happened? (You can include a screenshot if it helps explain)

If you have for instance MAKE_DIRECTORY in your ert config, then webviz ert will crash on startup (or config parsing) due to missing forward model:

ert vis poly.ert 
/data/komodo_dev/ert/test-data/ert/poly_example/poly.ert: Line 15 (Column 15-29): Could not find forward model step 'MAKE_DIRECTORY' in list of installed forward model steps: ['ECL2CSV', 'CSV2ECL', 'STEA', 'SUMO_UPLOAD_DEPRECATED', 'ECLCOMPRESS', 'PRTVOL2CSV', 'GRAV_SUBS_MAPS', 'ECLGRID2ROFF', 'MERGE_UNRST_FILES', 'INTERP_RELPERM', 'SUNSCH', 'WELLTEST_DPDS', 'GRAV_SUBS_POINTS', 'CSV2OFMVOL', 'MERGE_RFT_ERTOBS', 'ECLDIFF2ROFF', 'CSV_STACK', 'OFMVOL2CSV', 'ECLRST2ROFF', 'RI_WELLMOD', 'CASEGEN_UPCARS', 'CHECK_SWATINIT', 'PARAMS2CSV', 'ECLINIT2ROFF', 'CO2_PLUME_EXTENT', 'CO2_CONTAINMENT', 'GRID3D_AGGREGATE_MAP', 'GRID3D_MIGRATION_TIME', 'CO2_MASS_MAPS', 'CO2_PLUME_AREA', 'SIM2SUMO', 'run_completor', 'RES2CSV', 'CSV2RES', 'poly_eval']

What did you expect to happen?

Expect to be able to start webviz-ert.

steps to reproduce

Add `FORWARD_MODEL MAKE_DIRECTORY(<DIRECTORY>=some_dir)` to poly.ert, run ert simulation and then try to open webviz ert with, ert vis poly.ert

Environment where bug has been observed

• python 3.10
• python 3.11
• python 3.12
• macosx
• rhel7
• rhel8
• local queue
• lsf queue
• slurm queue
• openPBS queue