flasher: bump manifest to 2.7.1

The manifest version is hand-maintained and had drifted to 2.6.2 while the
binaries it served were v2.6.4 content.

Pushing this also re-deploys Pages via the `flash/**` path trigger, which is
the only trigger that actually works: the `release: published` trigger runs
from the tag ref and is rejected by the github-pages environment gate. It has
failed on every release since v2.6.3, and the deploys that appeared to work
were `main` pushes that happened to touch flash/ moments later. Without this
commit the flasher would keep serving v2.6.4 binaries.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: daniel-frenkel

flash/manifest.json

@@ -1,6 +1,6 @@
 {
   "name": "Ropener",
-  "version": "2.6.2",
+  "version": "2.7.1",
   "home_assistant_domain": "esphome",
   "new_install_prompt_erase": false,
   "builds": [