Remove unsafe use of transactions in Cypher export

[loveleif]

Remove unsafe use of transactions. Attempt to fix:

• https://trello.com/c/gRSYmlRs/2615-nightly-test-failure-apocexportcypherexportcyphermultireltestcreateoptimizationnone-is-failing-in-a-pipeline-run
• https://trello.com/c/Il7Rm3eN/2605-nightly-test-failure-apocexportcypherexportcyphermultireltestaddstructurewithoptimization-is-failing-in-a-pipeline-run
• https://trello.com/c/OwcxoHDR/2612-merge-test-failure-apocexportcypherexportcyphermultireltestupdatestructurewithoptimization-is-failing-in-a-pipeline-run
• https://trello.com/c/XpmvYy8q/2613-merge-test-failure-apocexportcypherexportcyphermultireltestcreatewithoptimization-is-failing-in-a-pipeline-run
• https://trello.com/c/uHttAONj/2614-merge-test-failure-apocrefactorgraphrefactoringtestshouldalwaysoverridenodepropsifnotsetandcombinerelpropsifpropertyisnull-is-fa
• https://trello.com/c/gXx1BFjd/2606-nightly-test-failure-apocexportcypherexportcyphermultireltestaddstructureoptimizationnone-is-failing-in-a-pipeline-run
• https://trello.com/c/wwnm2ff0/2609-nightly-test-failure-apocexportcypherexportcyphermultireltestaddstructurewithoptimizationandwithoutnodecleanup-is-failing-in-a-p
• https://trello.com/c/kItzqAwx/2611-nightly-test-failure-apocexportcypherexportcyphermultireltestupdateallwithoptimization-is-failing-in-a-pipeline-run
• https://trello.com/c/7F3kPehS/2610-nightly-test-failure-apocexportcypherexportcyphermultireltestupdatestructureoptimizationnone-is-failing-in-a-pipeline-run
• https://trello.com/c/UlIzEz4s/2607-nightly-test-failure-apocexportcypherexportcyphermultireltestupdatealloptimizationnone-is-failing-in-a-pipeline-run