[receiver/mongodbatlas] Fix memory leak (#32206) #32

Job	Run time
collector-build	7m 0s
docker-build	7m 19s
supervisor-test	56s
kubernetes-test-matrix (v1.26.0, receiver/k8sclusterreceiver)	4m 48s
kubernetes-test-matrix (v1.26.0, processor/k8sattributesprocessor)	4m 37s
kubernetes-test-matrix (v1.26.0, receiver/kubeletstatsreceiver)	4m 10s
kubernetes-test-matrix (v1.26.0, receiver/k8sobjectsreceiver)	3m 10s
kubernetes-test-matrix (v1.25.3, receiver/k8sclusterreceiver)	4m 45s
kubernetes-test-matrix (v1.25.3, processor/k8sattributesprocessor)	4m 25s
kubernetes-test-matrix (v1.25.3, receiver/kubeletstatsreceiver)	4m 9s
kubernetes-test-matrix (v1.25.3, receiver/k8sobjectsreceiver)	3m 29s
kubernetes-test-matrix (v1.24.7, receiver/k8sclusterreceiver)	4m 44s
kubernetes-test-matrix (v1.24.7, processor/k8sattributesprocessor)	4m 44s
kubernetes-test-matrix (v1.24.7, receiver/kubeletstatsreceiver)	4m 35s
kubernetes-test-matrix (v1.24.7, receiver/k8sobjectsreceiver)	3m 26s
kubernetes-test-matrix (v1.23.13, receiver/k8sclusterreceiver)	4m 43s
kubernetes-test-matrix (v1.23.13, processor/k8sattributesprocessor)	4m 28s
kubernetes-test-matrix (v1.23.13, receiver/kubeletstatsreceiver)	4m 14s
kubernetes-test-matrix (v1.23.13, receiver/k8sobjectsreceiver)	3m 25s
kubernetes-test	1s
	1h 23m 8s

Provide feedback