Race condition: program invocation can occur before trampoline table is populated

## Summary

A race condition exists in `_ebpf_program_type_specific_program_information_attach_provider()` where `program->extension_program_data` is set to non-NULL **before** the trampoline table is updated via `_ebpf_program_update_helpers()`. This allows program invocation to occur with a stale or uninitialized trampoline table, leading to calls into invalid helper function addresses.

## Root Cause Analysis

### The Race Window

In `libs/execution_context/ebpf_program.c`, the attach provider function has this sequence:

```c
// Line 532-533: Comment acknowledges the issue!
// "This should be done after the call to NmrClientAttachProvider, but _ebpf_program_update_helpers requires
// the program information to be set."

// Line 536: Unblock calls to use the program information - ENABLES INVOCATION
program->extension_program_data = extension_program_data;

// Line 538: Initialize rundown protection
ExInitializeRundownProtection(&program->program_information_rundown_reference);

// Line 543: Update helpers - POPULATES TRAMPOLINE TABLE (too late!)
if (_ebpf_program_update_helpers(program) != EBPF_SUCCESS) {
...
}
```

### The Invocation Check

In `ebpf_program_invoke()` (line 1536):

```c
// Check if extension_program_data is non-NULL (allows invocation)
if (ReadPointerNoFence((void* const volatile*)(&program->extension_program_data)) == NULL) {
*result = 0;
return EBPF_EXTENSION_FAILED_TO_LOAD;
}
```

As soon as `extension_program_data` is set to non-NULL, invocations are permitted. The JIT code will use the trampoline table to call helper functions.

### Race Sequence

| Time | Attach Thread | Invoke Thread (e.g., WFP callback) |
|------|---------------|------------------------------|
| T1 | Set `extension_program_data` (non-NULL) | |
| T2 | | Check `extension_program_data != NULL` → TRUE |
| T3 | | Get context_descriptor from extension_program_data |
| T4 | | Invoke JIT code |
| T5 | | JIT calls helper via trampoline table |
| T6 | `_ebpf_program_update_helpers()` runs | |
| T7 | | **CRASH: Trampoline has stale/uninitialized addresses!** |

At T5, the JIT code uses the trampoline table, but `_ebpf_program_update_helpers` hasn't populated it yet (or is running concurrently). The trampoline contains either:
- Old addresses from a previous provider instance
- Uninitialized/garbage addresses
- Addresses from a driver that has since unloaded

## Evidence

### Crash Observed

During concurrent attach/detach testing with driver stop/start between test runs, a crash was observed:

`
Child-SP RetAddr Call Site
ffffce05