要解决“AWS Lambda函数已被删除。无法恢复。”的问题，您可以尝试以下代码示例中的解决方法：

import boto3

def restore_deleted_lambda_function(function_name):
    client = boto3.client('lambda')
    
    # 获取删除的函数的相关信息
    response = client.list_functions()
    for function in response['Functions']:
        if function['FunctionName'] == function_name:
            deleted_function = function
            break
    
    # 创建一个新的Lambda函数
    response = client.create_function(
        FunctionName=deleted_function['FunctionName'],
        Runtime=deleted_function['Runtime'],
        Role=deleted_function['Role'],
        Handler=deleted_function['Handler'],
        Code={
            'S3Bucket': deleted_function['Code']['S3Bucket'],
            'S3Key': deleted_function['Code']['S3Key']
        },
        Description=deleted_function['Description'],
        Timeout=deleted_function['Timeout'],
        MemorySize=deleted_function['MemorySize'],
        Environment=deleted_function['Environment'],
        Tags=deleted_function['Tags']
    )
    
    # 将新函数的配置从已删除函数中复制过来
    function_configuration = client.get_function_configuration(
        FunctionName=deleted_function['FunctionName']
    )
    response = client.update_function_configuration(
        FunctionName=response['FunctionArn'],
        Role=function_configuration['Role'],
        Handler=function_configuration['Handler'],
        Description=function_configuration['Description'],
        Timeout=function_configuration['Timeout'],
        MemorySize=function_configuration['MemorySize'],
        Environment=function_configuration['Environment'],
        Tags=function_configuration['Tags']
    )
    
    print("已恢复Lambda函数：" + response['FunctionArn'])

# 使用示例
restore_deleted_lambda_function('deleted-function-name')

请注意，此代码示例假定您已配置并具有适当的AWS凭证。