[rubygems/rubygems] Improve Bundler errors when trying to install to a protected folder in macOS

### Before

```
$ GEM_HOME=/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/gems/2.6.0/ bundle
Fetching gem metadata from https://rubygems.org/.
Source rubygems repository https://rubygems.org/ or installed locally is ignoring #<Bundler::StubSpecification name=sqlite3 version=1.3.13 platform=ruby> because it is missing extensions
Source rubygems repository https://rubygems.org/ or installed locally is ignoring #<Bundler::StubSpecification name=nokogiri version=1.13.8 platform=ruby> because it is missing extensions
Source rubygems repository https://rubygems.org/ or installed locally is ignoring #<Bundler::StubSpecification name=libxml-ruby version=3.2.1 platform=ruby> because it is missing extensions
Resolving dependencies...
Fetching ruby2_keywords 0.0.5

Retrying download gem from https://rubygems.org/ due to error (2/4): Bundler::GenericSystemCallError There was an error accessing `/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/gems/2.6.0/cache/ruby2_keywords-0.0.5.gem`.
The underlying system error is Errno::EPERM: Operation not permitted @ rb_sysopen - /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/gems/2.6.0/cache/ruby2_keywords-0.0.5.gem

Retrying download gem from https://rubygems.org/ due to error (3/4): Bundler::GenericSystemCallError There was an error accessing `/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/gems/2.6.0/cache/ruby2_keywords-0.0.5.gem`.
The underlying system error is Errno::EPERM: Operation not permitted @ rb_sysopen - /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/gems/2.6.0/cache/ruby2_keywords-0.0.5.gem

Retrying download gem from https://rubygems.org/ due to error (4/4): Bundler::GenericSystemCallError There was an error accessing `/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/gems/2.6.0/cache/ruby2_keywords-0.0.5.gem`.
The underlying system error is Errno::EPERM: Operation not permitted @ rb_sysopen - /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/gems/2.6.0/cache/ruby2_keywords-0.0.5.gem

Bundler::GenericSystemCallError: There was an error accessing `/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/gems/2.6.0/cache/ruby2_keywords-0.0.5.gem`.
The underlying system error is Errno::EPERM: Operation not permitted @ rb_sysopen - /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/gems/2.6.0/cache/ruby2_keywords-0.0.5.gem
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/shared_helpers.rb:119:in `rescue in filesystem_access'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/shared_helpers.rb:104:in `filesystem_access'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/rubygems_integration.rb:431:in `block in download_gem'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/retry.rb:40:in `run'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/retry.rb:30:in `attempt'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/rubygems_integration.rb:423:in `download_gem'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/source/rubygems.rb:479:in `download_gem'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/source/rubygems.rb:436:in `fetch_gem'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/source/rubygems.rb:420:in `fetch_gem_if_possible'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/source/rubygems.rb:162:in `install'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/installer/gem_installer.rb:55:in `install'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/installer/gem_installer.rb:17:in `install_from_spec'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/installer/parallel_installer.rb:133:in `do_install'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/installer/parallel_installer.rb:124:in `block in worker_pool'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/worker.rb:62:in `apply_func'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/worker.rb:57:in `block in process_queue'
  <internal:kernel>:187:in `loop'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/worker.rb:54:in `process_queue'
  /Users/deivid/code/rubygems/rubygems/bundler/lib/bundler/worker.rb:90:in `block (2 levels) in create_threads'

An error occurred while installing ruby2_keywords (0.0.5), and Bundler cannot continue.

In Gemfile:
  ruby2_keywords
```

### After

```
$ GEM_HOME=/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/gems/2.6.0/ bundle
There was an error creating `/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/gems/2.6.0/bundler.lock`.
The underlying system error is Errno::EPERM: Operation not permitted @ rb_sysopen - /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/gems/2.6.0/bundler.lock
```

https://github.com/rubygems/rubygems/commit/345ec45f5a

0 files changed, 0 insertions, 0 deletions