Update mbed-os to master branch for last commit but got os v6.5.0

In Keil Studio, I want to acquire last commit of mbed-os and to update mbed-os version by Change Library Version feature.
After select master branch, my expectation is mbed-os v6.16.0 at least. However, the result is mbed-os-6.5.0-rc1~38.

After ARM added one more new tag mbed-os-6.17.0, I could get the right commit thru. this new tag.