v8.0.1

• Raised the floor to mobile_scanner >= 7.4.1, published a few hours after
  8.0.0's dependency audit. It fixes the false-positive
  plugins that apply Kotlin Gradle Plugin (KGP): mobile_scanner warning on
  AGP 9 by moving the plugin's Gradle files to the Kotlin DSL, and — more
  importantly — barcode scanning permanently stalling after a leaked camera
  frame, a host-app crash when CameraX fails to initialise, and an
  EXC_BAD_ACCESS on iOS when the app is terminated with the camera running.
  8.0.0's >=7.4.0 constraint already resolved 7.4.1 for a fresh pub get;
  this stops an existing lockfile from holding anyone on 7.4.0.
• Corrected the README's troubleshooting entry for that warning, which said it
  could not be fixed and would keep printing.
• Documented that upgrading across 7.4.0 -> 7.4.1 needs a flutter clean.
  That release moved the plugin's Gradle files from Groovy to the Kotlin DSL,
  and a build directory left over from 7.4.0 fails with
  cannot find symbol: class MobileScannerPlugin. Verified: the build fails
  incrementally and succeeds after a clean.