restore BROTLI_VERSION var in CMake build

PiperOrigin-RevId: 552495558

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index bf5204d..61378cd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -61,6 +61,7 @@
 read_macro("c/common/version.h" "BROTLI_VERSION_MAJOR" BROTLI_VERSION_MAJOR)
 read_macro("c/common/version.h" "BROTLI_VERSION_MINOR" BROTLI_VERSION_MINOR)
 read_macro("c/common/version.h" "BROTLI_VERSION_PATCH" BROTLI_VERSION_PATCH)
+set(BROTLI_VERSION "${BROTLI_VERSION_MAJOR}.${BROTLI_VERSION_MINOR}.${BROTLI_VERSION_PATCH}")
 mark_as_advanced(BROTLI_VERSION BROTLI_VERSION_MAJOR BROTLI_VERSION_MINOR BROTLI_VERSION_PATCH)
 
 # ABI Version information