task: Allow Rerun action to override properties of task being reran (#10468)

For example:
```
"alt-t": [
    "task::Rerun",
     { "reevaluate_context": true, "allow_concurrent_runs": true }
],
```
Overriding `allow_concurrent_runs` to `true` by itself should terminate
current instance of the task, if there's any.

This PR also fixes task deduplication in terminal panel to use expanded
label and not the id, which depends on task context. It kinda aligns
with how task rerun worked prior to #10341 . That's omitted in the
release notes though, as it's not in Preview yet.

Release Notes:

- `Task::Rerun` action can now override `allow_concurrent_runs` and
`use_new_terminal` properties of the task that is being reran.

crates/task/src/task_template.rs

@@ -102,7 +102,8 @@ impl TaskTemplate {
         let full_label = substitute_all_template_variables_in_str(&self.label, &task_variables)?;
         let command = substitute_all_template_variables_in_str(&self.command, &task_variables)?;
         let args = substitute_all_template_variables_in_vec(self.args.clone(), &task_variables)?;
-        let task_hash = to_hex_hash(self)
+
+        let task_hash = to_hex_hash(&self)
             .context("hashing task template")
             .log_err()?;
         let variables_hash = to_hex_hash(&task_variables)