new input data 6.75 and new CES parameters and gdx files SSP2EU and SSP2EU-EU21

[LaviniaBaumstark]

Purpose of this PR

new input data revision 6.75 and new CES parameters and gdx files for SSP2EU and SSP2EU-EU21,

calibration runs: /p/tmp/pehl/Remind/output/SSP2EU-NPi-calibrate_fast_2024-03-22_16.01.45 and /p/tmp/pehl/Remind/output/SSP2EU-EU21-NPi-calibrate_2024-03-18_16.23.52

Type of change

• [x] Minor change (default scenarios show only small differences)

Checklist:

• [x] My code follows the coding etiquette
• [x] I performed a self-review of my own code

Further information (optional):

• Test runs are here:
• Comparison of results (what changes by this PR?):