Don't use `DEPRECATE_HARD`

Otherwise, this branch won't be able to be compatible with 1.0 and 1.1.

script/build-libgit2.sh

@@ -68,7 +68,6 @@ cmake -DTHREADSAFE=ON \
       -DCMAKE_BUILD_TYPE="RelWithDebInfo" \
       -DCMAKE_INSTALL_PREFIX="${BUILD_INSTALL_PREFIX}" \
       -DCMAKE_INSTALL_LIBDIR="lib" \
-      -DDEPRECATE_HARD=ON \
       "${VENDORED_PATH}" &&
 
 exec cmake --build . --target install