.github: esp32_build: use default cmake package

[srmainwaring]

Use the default Ubuntu package for cmake rather than install the latest from kitware.

• The esp-idf requires a cmake minimum version of 3.16 (https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-guides/build-system.html#mandatory-parts)
• The Ubuntu 22.04 package for cmake installs version 3.22.1 (https://launchpad.net/ubuntu/jammy/+source/cmake).
• => default package from sudo apt install cmake meets requirements

[tpwrules]

Should probably be backported. What is the motivation for fixing this?

[srmainwaring]

@tpwrules there was a persistent esp32 build failure reported in the dev channel yesterday.

Cause was gpg key related, custom cmake install looked most likely candidate, though could not replicate the error.