Release 5.5.0 into trunk

[mokagio]

New version 5.5.0.

• @mokagio: Be sure to create a GitHub Release and tag once this PR gets merged.

Why?

Because we are still getting 429 errors when downloading ASC metadata from GlotPress and #406 fixes it.

Example: I run into this earlier when deploying a the localization smoke testing build for Jetpack/WordPress iOS

Downloading language: zh-Hant
[15:52:59]: No translation available for zh-Hant 👈👈👈
[15:52:59]: ---------------------
[15:52:59]: --- Step: git_add ---
[15:52:59]: ---------------------
[15:52:59]: Successfully added "/Users/gio/Developer/a8c/wpios/fastlane/metadata/**/*.txt" 💾.
[15:52:59]: ------------------------
[15:52:59]: --- Step: git_commit ---
[15:52:59]: ------------------------
[15:52:59]: $ git status /Users/gio/Developer/a8c/wpios/fastlane/metadata/\*\*/\*.txt --porcelain
[15:52:59]: ▸ A  fastlane/metadata/ar-SA/release_notes.txt
[15:52:59]: ▸ A  fastlane/metadata/de-DE/release_notes.txt
[15:52:59]: ▸ A  fastlane/metadata/en-GB/release_notes.txt
[15:52:59]: ▸ A  fastlane/metadata/es-ES/release_notes.txt
[15:52:59]: ▸ A  fastlane/metadata/fr-FR/release_notes.txt
[15:52:59]: ▸ A  fastlane/metadata/he/release_notes.txt
[15:52:59]: ▸ A  fastlane/metadata/id/release_notes.txt
[15:52:59]: ▸ A  fastlane/metadata/it/release_notes.txt
[15:52:59]: ▸ A  fastlane/metadata/ko/release_notes.txt
[15:52:59]: ▸ A  fastlane/metadata/nl-NL/release_notes.txt
[15:52:59]: ▸ A  fastlane/metadata/ru/release_notes.txt
[15:52:59]: ▸ A  fastlane/metadata/sv/release_notes.txt
[15:52:59]: ▸ A  fastlane/metadata/tr/release_notes.txt
[15:52:59]: ▸ A  fastlane/metadata/zh-Hans/release_notes.txt
[15:52:59]: ▸ D fastlane/metadata/zh-Hant/description.txt 👈😭
[15:52:59]: ▸ D fastlane/metadata/zh-Hant/keywords.txt 👈😭
[15:52:59]: ▸ D fastlane/metadata/zh-Hant/name.txt 👈😭
[15:52:59]: ▸ D fastlane/metadata/zh-Hant/subtitle.txt 👈😭