01-tutorials - [Bug] Utils: delete_gateway called without required gateway_client argument

**In which component is this bug present?**

- [ ] 01-AgentCore-runtime
- [x] 02-AgentCore-gateway
- [ ] 03-AgentCore-identity
- [ ] 04-AgentCore-memory
- [ ] 05-AgentCore-tools
- [ ] 06-AgentCore-observability
- [ ] 07-AgentCore-E2E

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**Bug Description**
A clear and concise description of the bug.

`delete_all_gateways` calls `delete_gateway(gatewayId)` without passing the required `gateway_client` argument. This raises a missing argument error since delete_gateway is defined as `delete_gateway(gateway_client, gatewayId)`.

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