feat: include short SHA in CROSSPOINT_VERSION (#1728)

## Summary

* Includes short SHA in version string for better version tracking, so
it looks like `1.1.0-dev-feat-kosync-xpath-05c6cf8`
* Closes
https://github.com/crosspoint-reader/crosspoint-reader/issues/1247

---

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platformio.ini

@@ -69,7 +69,7 @@ lib_deps =
 extends = base
 build_flags =
   ${base.build_flags}
-  ; CROSSPOINT_VERSION is set by scripts/git_branch.py (includes current branch)
+  ; CROSSPOINT_VERSION is set by scripts/git_branch.py (includes branch + short SHA)
   -DENABLE_SERIAL_LOG
   -DLOG_LEVEL=2 ; Set log level to debug for development builds