fix: make passing gitconfig as a value optional

[Carles-Figuerola]

Description

Adding a boolean option to not create the kubernetes secret when git.config.enable is set to true. This allows gitconfigs with actual secret information to be stored in kubernetes through a different pipeline rather than have actual secrets stored in the values section of the helm release (valid for autmated deploys where the deployment metadata is stored somewhere public)

As an example, for simplifying git auth in our infrastructure, we use a gitconfig like this to transparently authenticate all git operations:

url "https://<USERNAME>:<PASSWORD>@git.mydomain.com/"]
        insteadOf = https://git.mydomain.com/
        insteadOf = ssh://git@git.mydomain.com/
        insteadOf = git@git.mydomain.com:

[hiddeco]

LGTM, thank you @Carles-Figuerola 🌻