chore(version): Bump Version to 1.6.1 #1262

Job	Run time
test / test-dart-vm (3.0.1)	1m 58s
test / test-dart-vm (stable)	1m 50s
native_test / test-dart-native (macos-latest)	2m 49s
native_test / test-dart-native (windows-latest)	3m 52s
ddc_test / test-dart-ddc (3.0.1, chrome)	1m 52s
ddc_test / test-dart-ddc (3.0.1, firefox)	2m 2s
ddc_test / test-dart-ddc (stable, chrome)	1m 53s
ddc_test / test-dart-ddc (stable, firefox)	2m 3s
dart2js_test / test-dart-2js (3.0.1, chrome)	2m 45s
dart2js_test / test-dart-2js (3.0.1, firefox)	3m 5s
dart2js_test / test-dart-2js (stable, chrome)	2m 31s
dart2js_test / test-dart-2js (stable, firefox)	2m 50s
	29m 30s

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