Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@web/pgadmin/static/js/PgTreeView/index.jsx`:
- Line 91: Change the concise-arrow forEach callbacks to block-bodied arrows
that explicitly perform their side effects and return nothing; e.g., replace the
single-expression callback in the n.children?.forEach(child =>
updateDescendants(child, val)); call with a block-bodied callback that calls
updateDescendants(child, val) inside braces, do the same for the forEach inside
collectAllCheckedNodes (which currently has a bare return;) and the third
flagged forEach at line 146 so none of the forEach callbacks have implicit
returns; this will satisfy the lint rule and keep intent explicit.
- Around line 126-131: The code mutates the parent-owned node data by setting
n.data.isIndeterminate, causing stale flags; instead stop mutating n.data and
create a wrapper object for each selected node (e.g., push { node: n,
isIndeterminate: state === 'indeterminate' } into allCheckedNodes) so
isIndeterminate is derived from checkedState/newState rather than stored on
n.data; update the selectionChange call-site and the backup-dialog consumer to
read isIndeterminate from the wrapper object (or the wrapper's property) instead
of node.data.isIndeterminate so the flag is always correct and never mutates the
original data.

Verify each finding against the current code and only fix it if needed.

Outside diff comments:
In `@web/pgadmin/static/js/PgTreeView/index.jsx`:
- Around line 233-238: The DefaultNode PropTypes are incorrect: replace the
obsolete props `tree` and `onNodeSelectionChange` with the actual props used by
the component (`isChecked` and `onToggle`). Update DefaultNode.propTypes so it
declares node: PropTypes.object, style: PropTypes.any, hasCheckbox:
PropTypes.bool, isChecked: PropTypes.bool, and onToggle: PropTypes.func (remove
`tree` and `onNodeSelectionChange`) to match the usages in DefaultNode.