chore: adopt the NAPALM driver standard

- CI moves to .gitea/workflows/ci.yml and calls the shared driver workflow
  of NAPALM/driver-standard; .github/ is gone.
- napalm-device-types >=4.21.1 is now declared: the driver imports
  MediaDriver, PortSpec and FingerprintRule from it, and CI used to
  install it by hand.
- requires-python >=3.10 (napalm-device-types needs it), LICENSE, README,
  CHANGELOG, py.typed, SPDX license string, setuptools>=77, version floors
  on the dev extra, links to git.netork.io; .gitignore as in the template.
- mypy strict for the package; napalm_sonos.sonos_driver is exempt for now
  (5 errors, two of them return types that differ from MediaDriver's),
  recorded in the quality baseline.
- Coverage floor 71 % (measured 71.30 %).

.gitea/workflows/ci.yml

@@ -0,0 +1,15 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+    tags: ["v*"]
+  pull_request:
+
+jobs:
+  driver:
+    uses: NAPALM/driver-standard/.gitea/workflows/driver.yml@main
+    with:
+      standard-ref: main
+    secrets:
+      PYPI_TOKEN: ${{ secrets.PYPI_TOKEN }}