Reduce to max of 2 retries

[hcorson-dosch-usgs]

In main codebase, drop from 5 to 2 max_tries within the retry() code chunk. This makes it consistent with how we've been running model runs on Tallgrass -- those have been run within the denali_glm_tests branch on Tallgrass, which makes this reduction and also times different parts of the run_glm3_model() Function. For the next full re-runs I'd like to run on the main branch and keep that drop in max_tries but not the timing variables, as they increase the size of the tibble returned by run_glm3_model()

[hcorson-dosch-usgs]

Merging b/c already tested and very minor