iOS Ruby Updates (#32456)

Summary:
Fix the `scripts/update-ruby.sh` so it always use the correct [bundle config](https://bundler.io/man/bundle-config.1.html#DESCRIPTION). In the current version it wasn't using the correct configuration inside the `template/` directory, resulting in incorrect platform for `template/Gemfile.lock`.

While at that, update the gems to their latest version:
- ethon 0.14.0 -> 0.15.0
- json 0.5.1 -> 0.6.0
- zeitwerk 2.4.2 -> 2.5.1
- bundler 2.2.28 -> 2.2.29

No changelog

Pull Request resolved: #32456

Test Plan:
Run `bump-oss-version.js` and see `template/Gemfile.lock` lists `ruby` as the `PLATFORM` (no diff in that line).

 - e18cf90#r58230816

Reviewed By: yungsters

Differential Revision: D31841524

Pulled By: charlesbdudley

fbshipit-source-id: 695c245fcb344c866afed45f747e04233e5c91e4

Gemfile.lock

@@ -85,7 +85,7 @@ GEM
       colored2 (~> 3.1)
       nanaimo (~> 0.3.0)
       rexml (~> 3.2.4)
-    zeitwerk (2.4.2)
+    zeitwerk (2.5.1)
 
 PLATFORMS
   ruby
@@ -94,7 +94,7 @@ DEPENDENCIES
   cocoapods (~> 1.11, >= 1.11.2)
 
 RUBY VERSION
-   ruby 2.6.3p62
+   ruby 2.7.4p191
 
 BUNDLED WITH
-   1.17.2
+   2.2.29

scripts/update-ruby.sh

@@ -55,6 +55,9 @@ sed_i -e "s/^\(ruby '\)[^']*\('.*\)$/\1$VERSION\2/" template/Gemfile
 
 rm -f Gemfile.lock template/Gemfile.lock
 
+export BUNDLE_APP_CONFIG="$ROOT/.bundle"
+cp "$BUNDLE_APP_CONFIG/"* template/_bundle # sync!
+
 bundle lock
 (cd template && bundle lock)
 

template/Gemfile.lock

@@ -85,7 +85,7 @@ GEM
       colored2 (~> 3.1)
       nanaimo (~> 0.3.0)
       rexml (~> 3.2.4)
-    zeitwerk (2.4.2)
+    zeitwerk (2.5.1)
 
 PLATFORMS
   ruby
@@ -94,7 +94,7 @@ DEPENDENCIES
   cocoapods (~> 1.11, >= 1.11.2)
 
 RUBY VERSION
-   ruby 2.6.3p62
+   ruby 2.7.4p191
 
 BUNDLED WITH
-   1.17.2
+   2.2.29