chore: Elixir 1.17.1, Erlang 27.0

[bklebe]

Summary of changes

Asana Ticket: [extra] 🧠 Concentrate Erlang 27, Elixir 1.17

Bumps Erlang to 27.0 and Elixir to 1.17.1. Updates gpb, StreamData, and Credo to compatible versions; fixes compiler warnings about negative range steps.

[github-actions]

Coverage of commit 632f6d8

Summary coverage rate:
  lines......: 91.6% (1481 of 1617 lines)
  functions..: 72.3% (434 of 600 functions)
  branches...: no data found

Files changed coverage rate: n/a

Download coverage report

[github-actions]

Coverage of commit 7529b2c

Summary coverage rate:
  lines......: 91.6% (1481 of 1617 lines)
  functions..: 72.3% (434 of 600 functions)
  branches...: no data found

Files changed coverage rate: n/a

Download coverage report

[bfauble]

looks good from what I can tell, can you put it up on a dev environment just to sanity check there's no unexpected errors/behavior?

[bklebe]

@bfauble looks good in Splunk: https://mbta.splunkcloud.com/en-US/app/search/search?q=search%20index%3Dconcentrate-devgreen%20%22%5Berror%5D%22%20OR%20%22%5Bwarning%5D%22&sid=1719502677.3868851&display.page.search.mode=fast&dispatch.sample_ratio=1&workload_pool=&earliest=-30m%40m&latest=now