fix(macros): drop anyhow dependency from workflow_methods expansion

The `#[workflow_methods]` macro expanded to code that referenced
`::anyhow::Error` directly, forcing every downstream crate using the
proc-macro workflow API to add a direct `anyhow` dependency even when
its application code did not use `anyhow`.

Add a `From<workflows::WorkflowError> for WorkflowTermination` impl
that delegates to the existing `PayloadConversionError`/`anyhow::Error`
conversions, and have the macro convert the `serialize_result` error
through that impl instead of constructing an `anyhow::Error` itself.

Fixes #1245

Author: pranc1ngpegasus

crates/macros/src/workflow_definitions.rs

@@ -1012,7 +1012,7 @@ impl WorkflowMethodsDefinition {
                 let result = #run_call;
                 match result {
                     Ok(value) => ::temporalio_sdk::workflows::serialize_result(value, &ctx.payload_converter())
-                        .map_err(|e| ::temporalio_sdk::WorkflowTermination::from(::anyhow::Error::new(e))),
+                        .map_err(::temporalio_sdk::WorkflowTermination::from),
                     Err(e) => Err(e),
                 }
             }.boxed_local()

crates/sdk/src/lib.rs

@@ -1281,6 +1281,15 @@ impl From<temporalio_common::data_converters::PayloadConversionError> for Workfl
     }
 }
 
+impl From<workflows::WorkflowError> for WorkflowTermination {
+    fn from(err: workflows::WorkflowError) -> Self {
+        match err {
+            workflows::WorkflowError::PayloadConversion(e) => Self::from(e),
+            workflows::WorkflowError::Execution(e) => Self::from(e),
+        }
+    }
+}
+
 impl From<ActivityExecutionError> for WorkflowTermination {
     fn from(value: ActivityExecutionError) -> Self {
         Self::Failed(value.into())