esp32: Fix Python cstack size for bluetooth irq callbacks.

This value should have been adjusted when the new cstack API was adopted in
e3955f42, as otherwise the stack limit is too small especially on
ESP32-C3 where the stack limit was 6144 - 2048 - 2048.

Some extra margin is needed for bluetooth irq because invoke_irq_handler()
isn't a top-level task function, NimBLE calls through multiple layers
first. Measuring this overhead on IDF V5.2.2 (by putting an abort() in
invoke_irq_handler() and then measuring the stack size) yielded 672 bytes
on ESP32-S3 and 612 bytes on ESP32-C3, similar to the size reported in
cd66aa05.

Sticking with 1024 bytes for added safety margin. This means on Xtensa the
total margin for the BLE task stays the same (2048 bytes) as before
switching to cstack.

This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>

ports/esp32/mpconfigport.h

@@ -101,7 +101,10 @@
 #define MICROPY_PY_BLUETOOTH                (1)
 #define MICROPY_PY_BLUETOOTH_USE_SYNC_EVENTS (1)
 #define MICROPY_PY_BLUETOOTH_USE_SYNC_EVENTS_WITH_INTERLOCK (1)
-#define MICROPY_PY_BLUETOOTH_SYNC_EVENT_STACK_SIZE (CONFIG_BT_NIMBLE_TASK_STACK_SIZE - 2048)
+// Event stack size is the RTOS stack size minus an allowance for the stack used
+// by the NimBLE functions that call into invoke_irq_handler().
+// MICROPY_STACK_CHECK_MARGIN is further subtracted from this value to set the stack limit.
+#define MICROPY_PY_BLUETOOTH_SYNC_EVENT_STACK_SIZE (CONFIG_BT_NIMBLE_TASK_STACK_SIZE - 1024)
 #define MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE (1)
 #define MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING (1)
 #define MICROPY_BLUETOOTH_NIMBLE            (1)