Add BSD-2-Clause to allowed licenses #4362

Job	Run time
check linter (ubuntu-latest / stable)	1m 22s
test (ubuntu-latest / stable)	7m 57s
test (macos-latest / stable)	8m 43s
test (windows-latest / stable)	11m 24s
check feature flags (ubuntu-latest / stable)	8m 30s
check docs (ubuntu-latest / stable)	1m 15s
check examples (ubuntu-latest / stable)	1m 4s
check format (ubuntu-latest / nightly)	14s
check licenses (ubuntu-latest / stable)	25s
check minimal versions of transitive dependencies (ubuntu-latest / stable)	53s
check minimal supported rust version (ubuntu-latest / msrv)	34s
check spelling (ubuntu-latest / nightly)	5m 54s
	48m 15s

Provide feedback