Changes proposed in this Pull Request

• Adding another check whether carriers in the solved network also exist in n.statistics.energy_balance()
• Needed for those cases where inactive links (e.g. inactive CO2 pipelines) exist, but do not appear in energy balance. In this case, the previous workflow would break

carriers_in_eb = carriers[carriers.isin(eb.index.get_level_values("carrier"))]
eb.loc[components] = eb.loc[components].drop(index=carriers_in_eb, level="carrier")

Checklist

• I tested my contribution locally and it works as intended.
• Code and workflow changes are sufficiently documented.