Follow redirects for ktlint download

[gmackall]

The github release page is redirecting, so follow the redirects.

Good news, the uploading is working and the cipd package is created: https://chrome-infra-packages.appspot.com/p/flutter/ktlint/linux-amd64

Bad news, the uploaded ktlint file is empty because the curl is failing because we aren't following the redirect.

Passing the -L to curl fixes this (I double checked that with -L passed locally, we download a working version of ktlint). Sorry, should have caught this in the original PR.

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I read the Flutter Style Guide recently, and have followed its advice.
• I signed the CLA.
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is test-exempt.
• All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel on Discord.

[gmackall]

Also verifiable in the presubmit step here that we are actually downloading something
https://logs.chromium.org/logs/flutter/buildbucket/cr-buildbucket/8754355472971472689/+/u/build_package/stdout

curl -L https://github.com/pinterest/ktlint/releases/download/1.1.1/ktlint -o /b/s/w/ir/x/w/cocoon/cipd_packages/ktlint/tools/../build/ktlint
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed

  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0

 34 67.0M   34 23.3M    0     0  49.5M      0  0:00:01 --:--:--  0:00:01 49.5M
100 67.0M  100 67.0M    0     0   105M      0 --:--:-- --:--:-- --:--:--  266M

[gmackall]

Sorry for the spam, this will hopefully be the last of the cocoon ktlint prs 🙏

[keyonghan]

LGTM