How can I set a default config for cloned repositories? Is this possible, or is the config somehow stored in the repository?

Context:

• I have set the global config core.filemode = false
• I create an empty repository on GitHub. (i.e. I expect no ‘forced’ or ‘non-default’ config overrides)

I execute git clone https://<repository>

I inspect ./<repository>/.git/config

Expected

the config file should not contain core.filemode, or have core.filemode = false since this is what I configured globally.

Actual

The clone doesn’t follow my global setting:

$ git config --global core.filemode
false
$ head -n 3 .git/config 
[core]
    repositoryformatversion = 0
    filemode = true
$ 

Is there a reason why the clone is overriding my global setting? Is it GitHub? Is there a way to remedy this?