Bugfix: scan wifi asynchronously

[Staars]

Description:

Since our beloved watchdog has returned, we need to scan asynchronously. I am pretty sure, the delay could be longer, but in the end it will not matter much.

Related to: https://github.com/arendst/Tasmota/issues/21492

@btsimonh Can you try this?

Checklist:

• [x] The pull request is done against the latest development branch
• [x] Only relevant files were touched
• [x] Only one feature/fix was added per PR and the code change compiles without warnings
• [x] The code change is tested and works with Tasmota core ESP8266 V.2.7.6
• [x] The code change is tested and works with Tasmota core ESP32 V.3.0.0
• [x] I accept the CLA.

NOTE: The code change must pass CI tests. Your PR cannot be merged unless tests pass

[arendst]

Thx.

[btsimonh]

thankyou @Staars. I thought I was going wonky, but I guess I was just the first to try this after the watchdog was enabled!. I will test tomorrow.... but I assume that you have solved it.