Remove opencensus exporter/receiver #1994

Job	Run time
CI - Contrib - GoReleaser / check-goreleaser (linux, amd64)	9m 8s
CI - Contrib - GoReleaser / check-goreleaser (linux, 386)	8m 47s
CI - Contrib - GoReleaser / check-goreleaser (linux, s390x)	9m 18s
CI - Contrib - GoReleaser / check-goreleaser (linux, ppc64le)	9m 26s
CI - Contrib - GoReleaser / check-goreleaser (linux, arm64)	9m 21s
CI - Contrib - GoReleaser / check-goreleaser (windows, amd64)	9m 10s
CI - Contrib - GoReleaser / check-goreleaser (windows, 386)	9m 9s
CI - Contrib - GoReleaser / check-goreleaser (darwin, amd64)	8m 44s
CI - Contrib - GoReleaser / check-goreleaser (linux, arm)	8m 43s
CI - Contrib - GoReleaser / check-goreleaser (darwin, arm64)	9m 42s
CI - Contrib - GoReleaser / docker-tests (linux, 386)	26s
CI - Contrib - GoReleaser / docker-tests (linux, amd64)	24s
CI - Contrib - GoReleaser / docker-tests (linux, arm64)	23s
CI - Contrib - GoReleaser / docker-tests (linux, arm)	25s
CI - Contrib - GoReleaser / docker-tests (linux, ppc64le)	34s
CI - Contrib - GoReleaser / docker-tests (linux, s390x)	27s
MSI tests / MSI Tests (msi)	1m 11s
Package tests / Package Tests (rpm)	35s
Package tests / Package Tests (deb)	25s
Package tests / Create GitHub Issue	0s
	1h 36m 18s

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