Remove input files imposing limits on subsidies

[fbenke-pik]

Purpose of this PR

Follow-up to #2175

Remove input data file f21_prop_fe_sub.cs4r, which is used to apply a factor for MEA and REF for fehos to limit subsidies. Instead, the proportional factor is now applied directly in mrremind::calcFETaxes as part of input data generation.

Remove input data file f21_max_fe_sub, which is used to apply absolute limits on subsidies for fegas, fehos and fesos for various regions. Instead, the limit is no applied directly in mrremind::calcFETaxes as part of input data generation.

Important: Applying the limits in calcFETaxes slightly changes the input data, as it is now done on ISO-country level before aggregation to regions and rounding. The factors were chosen to yield results close to the ones of the previous approach, but they will not be identical.

Related PR in mrremind: pik-piam/mrremind#741

Comparison runs can be found here:
/p/tmp/benke/model/remind_subsidy/compScen-ssp1-2025-10-06_11.26.30-H12.pdf
/p/tmp/benke/model/remind_subsidy/compScen-ssp2-2025-10-06_11.29.31-H12.pdf
/p/tmp/benke/model/remind_subsidy/compScen-ssp3-2025-10-06_11.30.09-H12.pdf

Plots to take a look at (judging from a previous PR) are: 4.5.3, 5.1.7.2, 5.1.7.3, 5.3.4.2, 5.3.4.3

Type of change

Indicate the items relevant for your PR by replacing ◻️ with ☑️.
Do not delete any lines. This makes it easier to understand which areas are affected by your changes and which are not.

Parts concerned

• ☑️ GAMS Code
• ◻️ R-scripts
• ◻️ Documentation (GAMS incode documentation, comments, tutorials)
• ☑️ Input data / CES parameters
• ◻️ Tests, CI/CD (continuous integration/deployment)
• ◻️ Configuration (switches in main.gms, default.cfg, and scenario_config*.csv files)
• ◻️ Other (please give a description)

Impact

• ◻️ Bug fix
• ◻️ Refactoring
• ◻️ New feature
• ◻️ Change of parameter values or input data (including CES parameters)
• ☑️ Minor change (default scenarios show only small differences)
• ◻️ Fundamental change of results of default scenarios

Checklist

Do not delete any line. Leave unfinished elements unchecked so others know how far along you are.
In the end all checkboxes must be ticked before you can merge.

• I executed the automated model tests (make test) after my final commit and all tests pass (FAIL 0)
• I adjusted the reporting in remind2 if and where it was needed
• I adjusted the madrat packages (mrremind and other packages involved) for input data generation if and where it was needed
• My code follows the coding etiquette
• I explained my changes within the PR, particularly in hard-to-understand areas
• I checked that the in-code documentation is up-to-date
• I adjusted forbiddenColumnNames in readCheckScenarioConfig.R in case the PR leads to deprecated switches
• I updated the CHANGELOG.md correctly (added, changed, fixed, removed, input data/calibration)

[laurinks]

Looks good to me. Thank you, @fbenke-pik, for making things more transparent and readable!

[LaviniaBaumstark]

do you also need to have new input data?

[fbenke-pik]

do you also need to have new input data?

Correct, this requires new input data and calibration.