Use class specific buildx instances

So we don't have to muck with the machine default, and can swap between configurations without tearing down the old builder.

lib/mrsk/commands/builder/multiarch.rb

@@ -12,7 +12,8 @@ class Mrsk::Commands::Builder::Multiarch < Mrsk::Commands::Builder::Base
   def push
     docker :buildx, :build,
       "--push",
-      "--platform linux/amd64,linux/arm64",
+      "--platform", "linux/amd64,linux/arm64",
+      "--builder", builder_name,
       "-t", config.absolute_image,
       *build_args,
       *build_secrets,
@@ -27,6 +28,6 @@ class Mrsk::Commands::Builder::Multiarch < Mrsk::Commands::Builder::Base
 
   private
     def builder_name
-      "mrsk-#{config.service}"
+      "mrsk-#{config.service}-multiarch"
     end
 end

lib/mrsk/commands/builder/multiarch/remote.rb

@@ -15,8 +15,16 @@ class Mrsk::Commands::Builder::Multiarch::Remote < Mrsk::Commands::Builder::Mult
   end
 
   private
+    def builder_name
+      super + "-remote"
+    end
+
+    def builder_name_with_arch(arch)
+      "#{builder_name}-#{arch}"
+    end
+
     def create_local_buildx
-      docker :buildx, :create, "--use", "--name", builder_name, builder_name_with_arch(local["arch"]), "--platform", "linux/#{local["arch"]}"
+      docker :buildx, :create, "--name", builder_name, builder_name_with_arch(local["arch"]), "--platform", "linux/#{local["arch"]}"
     end
 
     def append_remote_buildx
@@ -50,9 +58,4 @@ class Mrsk::Commands::Builder::Multiarch::Remote < Mrsk::Commands::Builder::Mult
     def remote
       config.builder["remote"]
     end
-
-    private
-      def builder_name_with_arch(arch)
-        "#{builder_name}-#{arch}"
-      end
 end

lib/mrsk/commands/builder/native/remote.rb

@@ -17,6 +17,7 @@ class Mrsk::Commands::Builder::Native::Remote < Mrsk::Commands::Builder::Native
     docker :buildx, :build,
       "--push",
       "--platform", platform,
+      "--builder", builder_name,
       "-t", config.absolute_image,
       *build_args,
       *build_secrets,
@@ -40,7 +41,7 @@ class Mrsk::Commands::Builder::Native::Remote < Mrsk::Commands::Builder::Native
     end
 
     def builder_name
-      "mrsk-#{config.service}"
+      "mrsk-#{config.service}-native-remote"
     end
 
     def builder_name_with_arch
@@ -61,8 +62,7 @@ class Mrsk::Commands::Builder::Native::Remote < Mrsk::Commands::Builder::Native
     end
 
     def create_buildx
-      docker :buildx, :create,
-        "--use", "--name", builder_name, builder_name_with_arch, "--platform", platform
+      docker :buildx, :create, "--name", builder_name, builder_name_with_arch, "--platform", platform
     end
 
     def remove_buildx