README.md: remove deprecated option in example

replace `-DAVIF_CODEC_AOM=ON -DAVIF_LOCAL_AOM=ON` with
`-DAVIF_CODEC_AOM=LOCAL`.

missed in:
c92d9ec Do not use AVIF_LOCAL for libxml2 and gtest. (#2097)
diff --git a/README.md b/README.md
index 8efb46b..dc19ecb 100644
--- a/README.md
+++ b/README.md
@@ -140,7 +140,7 @@
 ./libjpeg.cmd
 ./zlibpng.cmd
 cd ..
-cmake -S . -B build -DBUILD_SHARED_LIBS=OFF -DAVIF_CODEC_AOM=ON -DAVIF_LOCAL_AOM=ON -DAVIF_LIBYUV=LOCAL -DAVIF_LIBSHARPYUV=LOCAL -DAVIF_JPEG=LOCAL -DAVIF_ZLIBPNG=LOCAL -DAVIF_BUILD_APPS=ON
+cmake -S . -B build -DBUILD_SHARED_LIBS=OFF -DAVIF_CODEC_AOM=LOCAL -DAVIF_LIBYUV=LOCAL -DAVIF_LIBSHARPYUV=LOCAL -DAVIF_JPEG=LOCAL -DAVIF_ZLIBPNG=LOCAL -DAVIF_BUILD_APPS=ON
 cmake --build build --parallel
 ```