Use newer rc4 tag in examples

docs/reference/rpc.mdx

@@ -205,7 +205,7 @@ helm repo update stellar
 ```bash
 helm install my-rpc stellar/soroban-rpc \
 --namespace my-rpc-namespace-on-cluster \
---set global.image.sorobanRpc.tag=20.0.0-rc3-39 \
+--set global.image.sorobanRpc.tag=20.0.0-rc4-40 \
 --set sorobanRpc.ingress.host=myrpc.example.org \
 --set sorobanRpc.persistence.enabled=true \
 --set sorobanRpc.persistence.storageClass=default \
@@ -266,7 +266,7 @@ Here's how to run the [soroban-rpc docker image](https://hub.docker.com/r/stella
 1. Pull the image at the version you'd like to run from [the tags](https://hub.docker.com/r/stellar/soroban-rpc/tags):
 
 ```bash
-docker pull stellar/soroban-rpc:20.0.0-rc3-39
+docker pull stellar/soroban-rpc:20.0.0-rc4-40
 ```
 
 2. Create a configuration file for [Stellar Core](https://github.com/stellar/stellar-core). Here is a sample configuration file for Testnet:
@@ -310,7 +310,7 @@ HISTORY="curl -sf http://history.stellar.org/prd/core-testnet/core_testnet_003/{
 
 ```bash
 docker run -p 8001:8001 -p 8000:8000 \
--v <STELLAR_CORE_CONFIG_FOLDER>:/config stellar/soroban-rpc:20.0.0-rc3-39 \
+-v <STELLAR_CORE_CONFIG_FOLDER>:/config stellar/soroban-rpc:20.0.0-rc4-40 \
 --captive-core-config-path="/config/<STELLAR_CORE_CONFIG_PATH>" \
 --captive-core-storage-path="/var/lib/stellar/captive-core" \
 --captive-core-use-db=true \
@@ -330,14 +330,14 @@ For production, we recommend running Soroban RPC with a [TOML](https://toml.io/e
 
 ```bash
 docker run -p 8001:8001 -p 8000:8000 \
--v <CONFIG_FOLDER>:/config stellar/soroban-rpc:20.0.0-rc3-39 \
+-v <CONFIG_FOLDER>:/config stellar/soroban-rpc:20.0.0-rc4-40 \
 --config-path <RPC_CONFIG_FILENAME>
 ```
 
 You can use Soroban RPC itself to generate a starter configuration file:
 
 ```bash
-docker run stellar/soroban-rpc:20.0.0-rc3-39 gen-config-file > soroban-rpc-config.toml
+docker run stellar/soroban-rpc:20.0.0-rc4-40 gen-config-file > soroban-rpc-config.toml
 ```
 
 The resulting configuration should look like this: