Configure CI workflow to compile AceTime library example

[per1234]

This change causes the "Compile Examples" CI workflow to compile AceTime library's "HelloDateTime" example sketch for
every board in the job matrix.

[per1234]

One of the library's example sketches will only compile for the ESP8266 and ESP32, so this made it impossible to compile the entire contents of the examples folder. I chose the "HelloDateTime" example as a representative sketch, but I'm happy to add additional examples if you want better coverage of the library.

[facchinm]

AceCommon compilation is failing due to namespace confusion on Print class. However, I'm merging and fixing that one in a separate commit.