Chart: Make Git-Sync DAG mount path configurable

[Subham-KRLX]

This PR allows users to configure the Git Sync destination directory via dags.gitSync.link (defaulting to "repo" for backward compatibility).

What changed

• Added dags.gitSync.link to values and schema.
• Updated sidecar environment variables and the airflow_dags helper to honor the custom link name.
• Updated documentation and release notes.

Why

Currently Git-Sync forces the DAG path to be /dags/repo/.... This fix enables customization for users who need a different directory structure.

closes: #65589

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Was generative AI tooling used to co-author this PR?

• Yes — Claude(for research)

[jscheffl]

I am not sure and following the bug ticket "why" thisis needed. In my view making this configurable adds un-needed complexity.

I would dis-like to merge additional complexity if there is no described need.

Side note: Plan mid-term is to remove gitsync completely from the chart and migrate to dag bundles. Adding new features to this inside the chart therefore is rather un-desired.

@mortazakiani as you opened the bug ticket asking for the feature, is there any rationale or convincing argument why this complexity should be added?

[jscheffl]

Marking request changed to block accidental merge

[Subham-KRLX]

I am not sure and following the bug ticket "why" thisis needed. In my view making this configurable adds un-needed complexity.

I would dis-like to merge additional complexity if there is no described need.

Side note: Plan mid-term is to remove gitsync completely from the chart and migrate to dag bundles. Adding new features to this inside the chart therefore is rather un-desired.

@mortazakiani as you opened the bug ticket asking for the feature, is there any rationale or convincing argument why this complexity should be added?

I am not sure and following the bug ticket "why" thisis needed. In my view making this configurable adds un-needed complexity.

I would dis-like to merge additional complexity if there is no described need.

Side note: Plan mid-term is to remove gitsync completely from the chart and migrate to dag bundles. Adding new features to this inside the chart therefore is rather un-desired.

@mortazakiani as you opened the bug ticket asking for the feature, is there any rationale or convincing argument why this complexity should be added?

@jscheffl the hardcoded "repo" directory breaks existing DAG setups when migrating to the Helm chart teams have to restructure their entire DAG paths just because of this hardcoded name I know git sync is being deprecated but users need this working now It's just one config option that defaults to current behavior.