Update scalafmt-core to 3.8.6 #1086

Job	Run time
Checks	1m 49s
Compile Benchmarks	1m 20s
Docs	2m 44s
Compile and test (2.12.20, 8)	3m 46s
Gradle tests	4m 18s
Maven tests	2m 50s
Compile and test (2.12.20, 11)	3m 31s
sbt scripted tests (gen-scala-server, 2.12)	8m 19s
Compile and test (2.12.20, 17)	4m 0s
sbt scripted tests (gen-java, 2.12)	3m 34s
Compile and test (2.12.20, 21)	3m 43s
Compile and test (2.13.16, 8)	4m 25s
Compile and test (2.13.16, 11)	4m 38s
Compile and test (2.13.16, 17)	4m 8s
Compile and test (2.13.16, 21)	4m 30s
Compile and test (3.3.4, 8)	4m 24s
Compile and test (3.3.4, 11)	4m 21s
Compile and test (3.3.4, 17)	4m 8s
Compile and test (3.3.4, 21)	3m 51s
	1h 14m 19s

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