Revert "[exporter][queuebatcher] set feature gate UsePullingBasedExporterQueueBatcher to beta" #27135

Job	Run time
govulncheck	32s
setup-environment	12s
lint	4m 40s
checks	2m 7s
test-coverage	9m 43s
cross-build-collector (darwin, amd64)	50s
unittest-matrix (ubuntu-latest, ~1.23)	5m 28s
cross-build-collector (darwin, arm64)	52s
unittest-matrix (ubuntu-latest, ~1.22)	5m 2s
cross-build-collector (linux, 386)	57s
cross-build-collector (linux, amd64)	45s
cross-build-collector (linux, arm64)	43s
cross-build-collector (linux, ppc64le)	46s
cross-build-collector (linux, arm, 7)	42s
cross-build-collector (linux, s390x)	39s
cross-build-collector (windows, 386)	47s
cross-build-collector (windows, amd64)	46s
unittest	1s
	35m 32s

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