Remove io sample (#2490)

This sample has been moved to my personal Github, because we shouldn't
maintain samples that are tied to events.

- Moved sample to personal repo
- Removed sample from this repo
- Updated README here and the link to this repo in the YouTube video

tool/flutter_ci_script_beta.sh

@@ -14,7 +14,6 @@ declare -ar PROJECT_NAMES=(
     "add_to_app/multiple_flutters/multiple_flutters_module"
     "add_to_app/plugin/flutter_module_using_plugin"
     "add_to_app/prebuilt_module/flutter_module"
-    "ai_recipe_generation"
     "analysis_defaults"
     "android_splash_screen"
     "animations"

tool/flutter_ci_script_master.sh

@@ -14,7 +14,6 @@ declare -ar PROJECT_NAMES=(
     "add_to_app/multiple_flutters/multiple_flutters_module"
     "add_to_app/plugin/flutter_module_using_plugin"
     "add_to_app/prebuilt_module/flutter_module"
-    "ai_recipe_generation"
     "analysis_defaults"
     "android_splash_screen"
     "animations"

tool/flutter_ci_script_stable.sh

@@ -14,7 +14,6 @@ declare -ar PROJECT_NAMES=(
     "add_to_app/multiple_flutters/multiple_flutters_module"
     "add_to_app/plugin/flutter_module_using_plugin"
     "add_to_app/prebuilt_module/flutter_module"
-    "ai_recipe_generation"
     "analysis_defaults"
     "android_splash_screen"
     "animations"