fix: bump soroban-sdk to 23.4.0 and OZ deps to v0.6.0

The CLI pulls OZ v0.6.0 examples which require soroban-sdk 23.4.0.
The template was pinned to soroban-sdk 23.1.0 and OZ v0.5.1, causing
compile errors (unknown `contracttrait` attribute, type mismatches).

Note: the CLI's dest_path fix (scaffold-stellar#451) will auto-update
the OZ tags going forward, but the soroban-sdk version still needs to
be compatible in the template as a baseline.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: oceans404

Cargo.toml

@@ -10,19 +10,19 @@ repository = "https://github.com/theahaco/scaffold-stellar"
 version = "0.0.1"
 
 [workspace.dependencies.soroban-sdk]
-version = "23.1.0"
+version = "23.4.0"
 
 [workspace.dependencies.stellar-access]
 git = "https://github.com/OpenZeppelin/stellar-contracts"
-tag = "v0.5.1"
+tag = "v0.6.0"
 
 [workspace.dependencies.stellar-macros]
 git = "https://github.com/OpenZeppelin/stellar-contracts"
-tag = "v0.5.1"
+tag = "v0.6.0"
 
 [workspace.dependencies.stellar-tokens]
 git = "https://github.com/OpenZeppelin/stellar-contracts"
-tag = "v0.5.1"
+tag = "v0.6.0"
 
 [profile.release]
 opt-level = "z"