Bump soroban-env to next protocol version (#595)

* Bump soroban-env to next protocol version
* Add required config key to mocked ledger entries
* Integrate unstable-next-api into curr (dropped arg)

Author: Shaptic

.github/workflows/stellar-rpc.yml

@@ -90,14 +90,12 @@ jobs:
     strategy:
       matrix:
         os: [ ubuntu-22.04 ]
-        protocol-version: [ 24, 25 ]
+        protocol-version: [ 25 ]
     runs-on: ${{ matrix.os }}
     env:
       STELLAR_RPC_INTEGRATION_TESTS_ENABLED: true
       STELLAR_RPC_INTEGRATION_TESTS_CORE_MAX_SUPPORTED_PROTOCOL: ${{ matrix.protocol-version }}
       STELLAR_RPC_INTEGRATION_TESTS_CAPTIVE_CORE_BIN: /usr/bin/stellar-core
-      PROTOCOL_24_CORE_DEBIAN_PKG_VERSION: 25.0.0-2911.e9748b05a.jammy
-      PROTOCOL_24_CORE_DOCKER_IMG: stellar/stellar-core:25.0.0-2911.e9748b05a.jammy
       PROTOCOL_25_CORE_DEBIAN_PKG_VERSION: 25.0.0-2911.e9748b05a.jammy
       PROTOCOL_25_CORE_DOCKER_IMG: stellar/stellar-core:25.0.0-2911.e9748b05a.jammy