Use DeleteBucketLifecycle with an AWS SDK or CLI

        /// <summary>
        /// This method removes the Lifecycle configuration from the named
        /// S3 bucket.
        /// </summary>
        /// <param name="client">The S3 client object used to call
        /// the RemoveLifecycleConfigAsync method.</param>
        /// <param name="bucketName">A string representing the name of the
        /// S3 bucket from which the configuration will be removed.</param>
        public static async Task RemoveLifecycleConfigAsync(IAmazonS3 client, string bucketName)
        {
            var request = new DeleteLifecycleConfigurationRequest()
            {
                BucketName = bucketName,
            };
            await client.DeleteLifecycleConfigurationAsync(request);
        }

The following command deletes a lifecycle configuration from a bucket named amzn-s3-demo-bucket:

aws s3api delete-bucket-lifecycle --bucket amzn-s3-demo-bucket

class BucketWrapper:
    """Encapsulates S3 bucket actions."""

    def __init__(self, bucket):
        """
        :param bucket: A Boto3 Bucket resource. This is a high-level resource in Boto3
                       that wraps bucket actions in a class-like structure.
        """
        self.bucket = bucket
        self.name = bucket.name


    def delete_lifecycle_configuration(self):
        """
        Remove the lifecycle configuration from the specified bucket.
        """
        try:
            self.bucket.LifecycleConfiguration().delete()
            logger.info(
                "Deleted lifecycle configuration for bucket '%s'.", self.bucket.name
            )
        except ClientError:
            logger.exception(
                "Couldn't delete lifecycle configuration for bucket '%s'.",
                self.bucket.name,
            )
            raise