utils/github/api: Fix uninitialized constant Etc

- I saw this in:

```
Error: uninitialized constant GitHub::API::Etc
Warning: Removed Sorbet lines from backtrace!
Rerun with `--verbose` to see the original backtrace
/opt/homebrew/Library/Homebrew/utils/github/api.rb:140:in `uid_home'
/opt/homebrew/Library/Homebrew/utils/github/api.rb:154:in `block in github_cli_token'
/opt/homebrew/Library/Homebrew/utils/uid.rb:8:in `drop_euid'
/opt/homebrew/Library/Homebrew/utils/github/api.rb:150:in `github_cli_token'
/opt/homebrew/Library/Homebrew/utils/github/api.rb:194:in `credentials'
/opt/homebrew/Library/Homebrew/utils/github/api.rb:251:in `open_rest'
/opt/homebrew/Library/Homebrew/utils/github/api.rb:334:in `open_graphql'
/opt/homebrew/Library/Homebrew/utils/github.rb:414:in `members_by_team'
/opt/homebrew/Library/Homebrew/dev-cmd/contributions.rb:71:in `run'
/opt/homebrew/Library/Homebrew/brew.rb:95:in `<main>'
```

Library/Homebrew/utils/github/api.rb

@@ -137,6 +137,7 @@ module GitHub
 
     sig { returns(T.nilable(String)) }
     private_class_method def self.uid_home
+      require "etc"
       Etc.getpwuid(Process.uid)&.dir
     rescue ArgumentError
       # Cover for misconfigured NSS setups