Update references to "default" or "current" lockfile to be "active"

The kwarg was changed from default to active quite a while ago

README.md

@@ -11,7 +11,7 @@ the default lockfile (Gemfile.lock), afterwhich all other lockfiles will
 be re-created based on this default lockfile. Additional lockfiles can be
 based on the same Gemfile, but vary at runtime. You can force a specific
 lockfile by setting the `BUNDLE_LOCKFILE` environment variable, or customize
-it any way you want by setting `current: true` on one of your lockfiles
+it any way you want by setting `active: true` on one of your lockfiles
 in your Gemfile.
 
 Alternately (or in addition!), you can define a lockfile to use a completely
@@ -85,7 +85,7 @@ with `BUNDLE_LOCKFILE`:
 BUNDLE_LOCKFILE=rails-7.0 bundle exec rspec
 ```
 
-You can also dynamically select it in your Gemfile, and pass `current: true`
+You can also dynamically select it in your Gemfile, and pass `active: true`
 to (exactly one!) `lockfile` method.
 
 ## Comparison to Appraisal

lib/bundler/multilock.rb

@@ -313,7 +313,7 @@ def loaded!
         end
         return unless default_lockfile_definition && default_lockfile_definition[:active] == false
 
-        raise GemfileEvalError, "No lockfiles marked as default"
+        raise GemfileEvalError, "No lockfiles marked as active"
       end
 
       # @!visibility private

spec/bundler/multilock_spec.rb

@@ -121,12 +121,12 @@
     end
   end
 
-  it "disallows no lockfile set as the default" do
+  it "disallows no lockfile set as active" do
     with_gemfile(<<~RUBY) do
       lockfile(default: false)
       lockfile("full")
     RUBY
-      expect { invoke_bundler("install") }.to raise_error(/No lockfiles marked as default/)
+      expect { invoke_bundler("install") }.to raise_error(/No lockfiles marked as active/)
     end
   end