Re-activate biosolids limit in industry for EUR to avoid increasing use of solids for chemicals

[leonieschweiger]

Purpose of this PR

Biosolids are limited to a share of 0.3 of total solids in industry, because solids biomass has limited substitution potential in both the steel and cement sector. However, this bound was removed for EUR in #2383 as a hotfix, because it was leading to increased EUR industry emissions in 2020-2030, due to some inconsistencies in the chemicals and cement sectors emissions. These were fixed in the meantime (#2442).
This PR therefore re-activates the bound for EUR, and thereby solves the issue that EUR saw in increasing use of solids for chemicals in PkBudg750 runs after the bound was removed (see https://github.com/remindmodel/development_issues/issues/780).

Type of change

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)

Further information (optional)

• Runs with these changes are here: /p/tmp/leoniesc/remind_clean2/output/v371dev3_biosolidFix_SSP2-NPi2025_2026-09-25_16.41.13 and /p/tmp/leoniesc/remind_clean2/output/v371dev3_biosolidFix_SSP2-PkBudg750_2026-09-25_20.20.14
• Comparison of results (what changes by this PR?):
  See below the plots of FE mix in Chemicals for the PkBudg750 runs for release v3.7.0.dev150 (when the issue came up), release v3.6.0 (.1 version, showing a run before the bound was introduced), the two development stages in between before and after the limit was removed for EUR, and the newest run where I turned on the limit again (v371dev3_biosolidFix).

[robertpietzcker]

looks good, thanks!