TECH-4787: delete :progname from context hash when we added it there

lib/contextual_logger.rb

@@ -106,7 +106,7 @@ def add(arg_severity, arg1 = nil, arg2 = nil, **context)   # Ruby will prefer to
         if arg1.nil?
           if block_given?
             message = yield
-            progname = arg2 || context[:progname] || @progname
+            progname = arg2 || context.delete(:progname) || @progname
           else
             message = arg2
             progname = @progname

spec/lib/contextual_logger_spec.rb

@@ -205,8 +205,16 @@ def expect_log_line_to_be_written(log_line)
       let(:message) { 'request: this is a test' }
 
       it 'handles message block (inline context) with progname' do
-        expect_log_line_to_be_written(expected_log_hash.merge(progname: 'request').to_json)
+        formatter_args = []
+        logger.formatter = -> (*args) do
+          formatter_args = args
+          '"message"'
+        end
+        expect_log_line_to_be_written('"message"')
         expect(logger.info('request', service: 'test_service') { 'this is a test' }).to eq(true)
+
+        expect(formatter_args[2]).to eq('request')
+        expect(formatter_args[3]).to eq(message: "this is a test", service: "test_service")
       end
     end