docs: Add troubleshooting note re. parsing race condition

[adwk67]

Description

Fixes #732

Local testing of affected DAGs:

--- PASS: kuttl (218.18s)
    --- PASS: kuttl/harness (0.00s)
        --- PASS: kuttl/harness/versioning_airflow-latest-3.0.6_openshift-false (217.55s)
PASS

and

--- PASS: kuttl (485.85s)
    --- PASS: kuttl/harness (0.00s)
        --- PASS: kuttl/harness/mount-dags-gitsync_airflow-latest-3.0.6_openshift-false_executor-celery_access-ssh (235.15s)
        --- PASS: kuttl/harness/mount-dags-gitsync_airflow-latest-3.0.6_openshift-false_executor-kubernetes_access-https (238.40s)
        --- PASS: kuttl/harness/mount-dags-gitsync_airflow-latest-3.0.6_openshift-false_executor-kubernetes_access-ssh (226.26s)
        --- PASS: kuttl/harness/mount-dags-gitsync_airflow-latest-3.0.6_openshift-false_executor-celery_access-https (250.09s)
PASS

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

Author

• Changes are OpenShift compatible
• CRD changes approved
• CRD documentation for all fields, following the style guide.
• Helm chart can be installed and deployed operator works
• Integration tests passed (for non trivial changes)
• Changes need to be "offline" compatible
• Links to generated (nightly) docs added
• Release note snippet added

Reviewer

• Code contains useful comments
• Code contains useful logging statements
• (Integration-)Test cases added
• Documentation added or updated. Follows the style guide.
• Changelog updated
• Cargo.toml only contains references to git tags (not specific commits or branches)

Acceptance

• Feature Tracker has been updated
• Proper release label has been added
• Links to generated (nightly) docs added
• Release note snippet added
• Add type/deprecation label & add to the deprecation schedule
• Add type/experimental label & add to the experimental features tracker

[maltesander]

LGTM!