Remove "<>" characters when publishing a new version to TestFlight

[nilsreichardt]

The App Store does not allow "<>" characters in the changelog.

The changes transforms the string from:

Fix "sz pub get" not running for all packages. (#448) Co-authored-by: Nils Reichardt <[email protected]>

Converting it to the following string worked:

Fix "sz pub get" not running for all packages. (#448) Co-authored-by: Nils Reichardt [email protected]

Tested it locally:

Closes #464

[nilsreichardt]

First I thought about replacing them (like with ()) but I think it's too overkill for now because it's makes it more complicated when we add other characters that are not allowed.