fix(engine): remove flow template (tari-project#1366)

Description
---
Removed flow template support.

Closes tari-project#1334

Motivation and Context
---

Flow templates were not used and outdated.

How Has This Been Tested?
---

What process can a PR reviewer use to test or verify this change?
---


Breaking Changes
---

- [ ] None
- [x] Requires data directory to be deleted
- [ ] Other - Please specify

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **Refactor**
- Removed support for flow-based templates, with system behavior now
focused on WASM and Manifest types for template execution and error
handling.
- **Chores**
- Cleaned up and streamlined internal processing by eliminating obsolete
flow components and related worker implementations.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Stan Bondi <sdbondi@users.noreply.github.com>

Author: ksrichard

Cargo.lock

@@ -561,9 +561,7 @@ impl JsonRpcHandlers {
                 .load_template()
                 .map_err(|e| Self::internal_error(answer_id, format!("Error loading template: {}", e)))?,
             // TemplateExecutable::DownloadableWasm is never returned ad there is no DB type for that
-            TemplateExecutable::DownloadableWasm(_, _) |
-            TemplateExecutable::Manifest(_) |
-            TemplateExecutable::Flow(_) => {
+            TemplateExecutable::DownloadableWasm(_, _) | TemplateExecutable::Manifest(_) => {
                 return Err(JsonRpcResponse::error(
                     answer_id,
                     JsonRpcError::new(

applications/tari_indexer/src/json_rpc/handlers.rs

@@ -99,13 +99,6 @@ impl TemplateSyncTask {
                             template_type: TemplateType::Manifest.into(),
                             template_name: template.metadata.name,
                         }),
-                        TemplateExecutable::Flow(flow) => Ok(SyncTemplatesResponse {
-                            address: template.metadata.address.to_vec(),
-                            author_public_key: template.metadata.author_public_key.to_vec(),
-                            binary: flow.into_bytes(),
-                            template_type: TemplateType::Flow.into(),
-                            template_name: template.metadata.name,
-                        }),
                         // this case won't happen as there is no DB type for downloadable WASM
                         TemplateExecutable::DownloadableWasm(_, _) => {
                             Err(RpcStatus::not_implemented("Unsupported type!"))

applications/tari_validator_node/src/p2p/rpc/template_sync_task.rs

@@ -23,13 +23,11 @@ tari_transaction = { workspace = true }
 anyhow = { workspace = true }
 blake2 = { workspace = true }
 cargo_toml = { workspace = true }
-d3ne = { workspace = true }
 log = { workspace = true, features = ["std"] }
 rand = { workspace = true }
 indexmap = { workspace = true }
 semver = { workspace = true }
 serde = { workspace = true, default-features = true }
-serde_json = { workspace = true }
 thiserror = { workspace = true }
 tempfile = { workspace = true }
 wasmer = { workspace = true, features = ["cranelift"] }