Use remote spec instead of a local one for Gutenberg via commit

The idea was to use a local spec and interpolated the desired commit
SHA1 in the `source` to download the corresponding `tar.gz`.

However, CocoaPods has some issues with local specs that use `http`
`source`, as documented in:

- CocoaPods/CocoaPods#10288 (comment)
- https://github.com/firebase/firebase-ios-sdk/blob/68b39b8edf61f6e643e2396e712c7c67e0f146ff/scripts/pod_lib_lint.rb#L70-L78

Using a remote spec doesn't have the same issue, and the cost in terms
of extra computation and storage is negligible when compared to building
and hosting the `tar.gz` archives.

.rubocop.yml

@@ -17,9 +17,6 @@ Metrics/MethodLength:
   Max: 30
   Exclude: *xfiles
 
-Metrics/BlockLength:
-  Exclude: *.podspec
-
 Layout/LineLength:
   Max: 180
   Exclude: *xfiles
@@ -40,4 +37,3 @@ Style/AsciiComments:
 Naming/FileName:
   Exclude:
     - fastlane/Matchfile
-    - Gutenberg/Gutenberg.podspec

Gutenberg/cocoapods_helpers.rb

@@ -89,9 +89,7 @@ def gutenberg_pod(config: GUTENBERG_CONFIG)
 
     gutenberg_dependencies(options: options)
   elsif options[:commit]
-    # Notice the use of relative path, otherwise we'd get the full path of the user that run the `pod install` command tracked in Podfile.lock.
-    # Also notice the path is relative from Dir.pwd, that is, the location where the script running this code is invoked to avoid absolute paths making the checksum non determinstic.
-    pod 'Gutenberg', path: Pathname.new(File.join(__dir__, 'Gutenberg.podspec')).relative_path_from(Dir.pwd).to_s
+    pod 'Gutenberg', podspec: "https://d2twmm2nzpx3bg.cloudfront.net/Gutenberg-#{options[:commit]}.podspec"
   end
 end
 # rubocop:enable Metrics/AbcSize
@@ -103,7 +101,7 @@ def gutenberg_dependencies(options:)
     tag = options[:tag]
     podspec_prefix = "https://raw.githubusercontent.com/#{GITHUB_ORG}/#{REPO_NAME}/#{tag}"
   elsif options[:commit]
-    return # when referencing via a commit, we donwload pre-built frameworks
+    return # when referencing via a commit, we download pre-built frameworks
   else
     raise "Unexpected Gutenberg dependencies configuration '#{options}'"
   end
@@ -118,8 +116,3 @@ def gutenberg_dependencies(options:)
     pod pod_name, podspec: "#{podspec_prefix}/#{pod_name}.#{podspec_extension}"
   end
 end
-
-def archive_url(commit:)
-  xcframework_storage_url = 'https://d2twmm2nzpx3bg.cloudfront.net'
-  "#{xcframework_storage_url}/Gutenberg-#{commit}.tar.gz"
-end

Gutenberg/version.rb

@@ -17,13 +17,3 @@
 
 GITHUB_ORG = 'wordpress-mobile'
 REPO_NAME = 'gutenberg-mobile'
-
-# The root working directory for downloading and extracting archives.
-# In this location because multiple sources access it.
-#
-# This path should be ignored by Git.
-GUTENBERG_WORKING_DIRECTORY = File.join(__dir__, '.build')
-# Where to download the XCFramework archives
-GUTENBERG_DOWNLOADS_DIRECTORY = File.join(GUTENBERG_WORKING_DIRECTORY, 'donwloads')
-# Where to extract the XCFramework archive version to use for the build.
-GUTENBERG_ARCHIVE_DIRECTORY = File.join(GUTENBERG_WORKING_DIRECTORY, 'archive')