Quality: Missing rp2350 DREQ_PIO2_* constants in rp2 module stubs

The `rp2` module stubs are missing the rp2350-specific `DREQ_PIO2_*` constants that were introduced for the RP2350's third PIO block. **Affected stub package**: `micropython-rp2-stubs` (and rp2350 board variants) **Affected module/symbols**: `rp2` — `DREQ_PIO2_TX0`, `DREQ_PIO2_TX1`, `DREQ_PIO2_TX2`, `DREQ_PIO2_TX3`, `DREQ_PIO2_RX0`, `DREQ_PIO2_RX1`, `DREQ_PIO2_RX2`, `DREQ_PIO2_RX3` **Current behavior**: These constants are absent from the stubs, causing type checkers to report undefined attribute errors when accessing e.g. `rp2.DREQ_PIO2_TX1`. **Expected behavior**: These constants should be defined in the `rp2` module stubs for rp2350 targets, as they are present in MicroPython firmware (see micropython/micropython#18974). **Reference / upstream test**: ```python self.assertEqual(rp2.DREQ_PIO2_TX1, 17) self.assertEqual(rp2.DREQ_PIO2_TX2, 18) self.assertEqual(rp2.DREQ_PIO2_TX3, 19) self.assertEqual(rp2.DREQ_PIO2_RX0, 20) self.assertEqual(rp2.DREQ_PIO2_RX1, 21) self.assertEqual(rp2.DREQ_PIO2_RX2, 22) self.assertEqual(rp2.DREQ_PIO2_RX3, 23) ``` Parent issue: #884 > Generated by [quality-issue-triage](https://github.com/Josverl/micropython-stubs/actions/runs/25610518322/agentic_workflow) · ● 232.4K · [◷](https://github.com/search?q=repo%3AJosverl%2Fmicropython-stubs+is%3Aissue+%22gh-aw-workflow-call-id%3A+Josverl%2Fmicropython-stubs%2Fquality-issue-triage%22&type=issues) <!-- gh-aw-agentic-workflow: quality-issue-triage, engine: copilot, version: 1.0.40, model: claude-sonnet-4.6, id: 25610518322, workflow_id: quality-issue-triage, run: https://github.com/Josverl/micropython-stubs/actions/runs/25610518322 --> <!-- gh-aw-workflow-id: quality-issue-triage --> <!-- gh-aw-workflow-call-id: Josverl/micropython-stubs/quality-issue-triage -->