upkeep: clean up `add_green_technologies_to_abcd()`

[jacobvjk]

r2dii.analysis/R/join_abcd_scenario.R

Line 168 in d5c0a15

green_rows_to_add <- data %>%

• green_rows_to_add() uses a summarize call to obtain the distinct rows of the abcd, using dplyr::distinct is more appropriate
• following this, a left_join is used to expand the abcd by missing low carbon technologies. this adds rows with NA values for all technologies that are not missing. There does not seem to be a reason for that, so an inner_join would be more adequate.