revised data set for SDM for scup in the spring

[gavinfay]

@CataRoman commit # dd505e2 adds specifications to revise the trawl survey data set for the distribution modeling for scup for the spring.
Specifically this:

• doesn't remove the 2017 survey (previously these data had been deleted)
• doesn't include nearshore strata
• limits data to tows done before julian day 120 to (primarily) remove tows from 2016 when northern and inshore strata weren't sampled until after scup had migrated inshore for summer.
• limits depth range to 50-140m

The revised data exploration Rmd contains the EDA that led to these decisions.

As requested I only looked at spring because that's what you said you were having trouble with.

[gavinfay]

@CataRoman I also notice that you are not using 2022 trawl survey data. I can understand not having the 2024 data, given that the survey only recently wrapped, but seems like 2022 should be in there (as well as 2023 for fall).