[rubygems/rubygems] Migrate some specs to use "the new way"

The commands these specs run were throwing warnings in bundler 2, and
failing on bundler 3, effectively testing a different scenario to what
they were supposed to.

https://github.com/rubygems/rubygems/commit/97ac1ced49

spec/bundler/cache/git_spec.rb

@@ -31,7 +31,7 @@ RSpec.describe "bundle cache with git" do
     expect(the_bundle).to include_gems "foo 1.0"
   end
 
-  it "copies repository to vendor cache and uses it even when installed with bundle --path" do
+  it "copies repository to vendor cache and uses it even when configured with `path`" do
     git = build_git "foo"
     ref = git.ref_for("master", 11)
 
@@ -39,7 +39,8 @@ RSpec.describe "bundle cache with git" do
       gem "foo", :git => '#{lib_path("foo-1.0")}'
     G
 
-    bundle "install --path vendor/bundle"
+    bundle "config set --local path vendor/bundle"
+    bundle "install"
     bundle "config set cache_all true"
     bundle :cache
 

spec/bundler/install/deploy_spec.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-RSpec.describe "install with --deployment or --frozen" do
+RSpec.describe "install in deployment or frozen mode" do
   before do
     gemfile <<-G
       source "#{file_uri_for(gem_repo1)}"
@@ -67,7 +67,8 @@ RSpec.describe "install with --deployment or --frozen" do
     skip "doesn't find bundle" if Gem.win_platform?
 
     bundle! :install
-    bundle "install --deployment"
+    bundle "config --local deployment true"
+    bundle :install
     bundle! "exec bundle check", :env => { "PATH" => path }
   end
 

spec/bundler/install/gemfile/gemspec_spec.rb

@@ -126,7 +126,8 @@ RSpec.describe "bundle install from an existing gemspec" do
     # ghost pass in future, and will only catch a regression if the message
     # doesn't change. Exit codes should be used correctly (they can be more
     # than just 0 and 1).
-    output = bundle("install --deployment", :dir => tmp.join("foo"))
+    bundle "config set --local deployment true"
+    output = bundle("install", :dir => tmp.join("foo"))
     expect(output).not_to match(/You have added to the Gemfile/)
     expect(output).not_to match(/You have deleted from the Gemfile/)
     expect(output).not_to match(/install in deployment mode after changing/)

spec/bundler/install/gemfile/git_spec.rb

@@ -124,7 +124,8 @@ RSpec.describe "bundle install with git sources" do
     end
 
     it "still works after moving the application directory" do
-      bundle "install --path vendor/bundle"
+      bundle "config --local path vendor/bundle"
+      bundle "install"
 
       FileUtils.mv bundled_app, tmp("bundled_app.bck")
 
@@ -132,7 +133,8 @@ RSpec.describe "bundle install with git sources" do
     end
 
     it "can still install after moving the application directory" do
-      bundle "install --path vendor/bundle"
+      bundle "config --local path vendor/bundle"
+      bundle "install"
 
       FileUtils.mv bundled_app, tmp("bundled_app.bck")