eth/tracers: report correct gasLimit in call tracers (#27029)

This includes a semantic change to the `callTracer` as well as `flatCallTracer`.
The value of field `gas` in the **first** call frame will change as follows:

- It previously contained gas available after initial deductions (i.e. tx costs)
- It will now contain the full tx gasLimit value

Signed-off-by: jsvisa <delweng@gmail.com>

eth/tracers/js/goja.go

@@ -235,7 +235,7 @@ func (t *jsTracer) CaptureStart(env *vm.EVM, from common.Address, to common.Addr
 	t.ctx["from"] = t.vm.ToValue(from.Bytes())
 	t.ctx["to"] = t.vm.ToValue(to.Bytes())
 	t.ctx["input"] = t.vm.ToValue(input)
-	t.ctx["gas"] = t.vm.ToValue(gas)
+	t.ctx["gas"] = t.vm.ToValue(t.gasLimit)
 	t.ctx["gasPrice"] = t.vm.ToValue(env.TxContext.GasPrice)
 	valueBig, err := t.toBig(t.vm, value.String())
 	if err != nil {