Optional task mutex (#69) #81

Job	Run time
Check formatting	14s
Unit test	55s
Build example (basic, release-v5.0, esp32)	1m 37s
Build example (basic, release-v5.1, esp32)	1m 54s
Build example (basic, release-v5.2, esp32)	1m 52s
Build example (basic, release-v5.3, esp32)	1m 56s
Build example (basic_i2c, release-v5.0, esp32)	1m 39s
Build example (basic_i2c, release-v5.1, esp32)	1m 52s
Build example (basic_i2c, release-v5.2, esp32)	1m 53s
Build example (basic_i2c, release-v5.3, esp32)	1m 52s
Build example (memory_dump, release-v5.0, esp32)	1m 36s
Build example (memory_dump, release-v5.1, esp32)	1m 53s
Build example (memory_dump, release-v5.2, esp32)	1m 50s
Build example (memory_dump, release-v5.3, esp32)	1m 57s
Build example (read_write, release-v5.0, esp32)	1m 37s
Build example (read_write, release-v5.1, esp32)	1m 53s
Build example (read_write, release-v5.2, esp32)	1m 53s
Build example (read_write, release-v5.3, esp32)	1m 47s
Build example (multiple_scanners, release-v5.0, esp32)	1m 41s
Build example (multiple_scanners, release-v5.1, esp32)	1m 53s
Build example (multiple_scanners, release-v5.2, esp32)	1m 57s
Build example (multiple_scanners, release-v5.3, esp32)	1m 53s
	37m 34s

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