ci: Properly capture username it git config

[btashton]

Summary

Git username that contained certain symbols such as Tomasz 'CeDeROM' CEDRO does not get captured properly when setting the git config in the workflow

~/nuttx-wrk/nuttx-website on  master via 💎 v3.0.2 
❯  username="`git log -1 --pretty=format:'%an'`"
email="`git log -1 --pretty=format:'%ae'`"
❯ echo $username
Tomasz 'CeDeROM' CEDRO
❯ echo $email
tomek@cedro.info
❯ git config user.name $username
usage: git config [<options>]

Config file location
    --global              use global config file
    --system              use system config file
....

With this change

❯ git config user.name "$username"
❯ git config user.name
Tomasz 'CeDeROM' CEDRO

[btashton]

@acassis / @cederom this will resolve the CI issue that was preventing the recent changes from being published.

[cederom]

Thank You @btashton :-)