[psteinroe]

Stacked on #975.

Removes code that nothing uses. I grepped for every item first. Clippy on the whole workspace is clean. pgls_workspace without the db feature has the same six warnings as before: ExecuteStatementMapper, TypecheckDiagnosticsMapper, IdFilter and Document::find are only used with db. Those are cfg-dependent, not dead, and this PR doesn't touch them.

Removed

• AnnotationStore (pgls_workspace/src/workspace/server/annotation.rs). Every Document built one and pruned and cleared it with the parse and tree caches, but nothing read it. The field had #[allow(dead_code)], and get_annotations had #[allow(unused)]. Its only test tested the store itself.
• pgls_hover::OnHoverParams::ast. Hover never read it, but the workspace looked up the statement's tree to pass it. on_hover now maps the statement with WithCSTMapper, and WithCSTandASTMapper, which had no other user, is gone.
• HoveredNode::Trigger, which was never constructed (#[allow(unused)]).
• Snapshot::find_types in pgls_catalog, which had no callers.
• SQLFunctionSignature::schema, which was set but never read (#[allow(dead_code)]).
• ClientInformation in pgls_lsp: initialize stored the client's name and version in the session, and nothing read them. They are still logged by the tracing::instrument on initialize.
• print_markup in pgls_lsp/src/utils.rs (#[allow(unused)]). It was the last use of pgls_console in pgls_lsp, so that dependency goes too.

Simplified

In pgls_hover::on_hover, the table and type branches each had an arm for "no schema" and one for "schema" that only differed in passing None or Some(&s). They pass schema.as_deref() now, which is the same. The column branches really differ (alias resolution) and stay as they are.

Kept

• Document::count and InitializeParams::workspace_folders had #[allow]s but are used (completions, workspace folder resolution). Only the attributes are removed.
• Migration::name is only read by tests, HoveredNode::Policy's payload is never read, but the variant stops policy names from being hovered as other objects, the #[allow(unused_variables)] on the execute_statement without db and the MapHolder test struct are cfg- or test-only. They are not dead.

Tests

pgls_workspace, pgls_lsp, pgls_hover and pgls_catalog pass, and so does clippy on the whole workspace.

[psteinroe]

Superseded by #989 (rebuild of the document caches and walk).