chore(datasource): remove deprecated add_row_stats (Closes #23080 - partial)

[Dodothereal]

Removes datafusion_datasource::add_row_stats (deprecated since 47.0.0 with replacement Statistics::add). Zero callers — the only references are the deprecated function definition and a single pub use re-export (carrying an explicit 'Remove when add_row_stats is remove' comment, indicating this was already acknowledged as future work). Pure 11-line deletion across 2 files. Closes #23080 (partial - fourth in housekeeping series after #23129, #23131, #23132). AI assistance: used an AI coding assistant; verified via repo-wide grep that the function has no callers.

[Dodothereal]

Re-pinging: this PR is a 7-line removal of add_row_stats() in ListingOptions (deprecated since 1bc7aaa; follow-up to #22983 and closes part of #23080). cargo-semver-checks workflow may need re-running — happy to re-push if needed. (Continuation of the started sweep #23129 / #23131 / #23132 which landed.)

[Dodothereal]

@alamb (and any other reviewer) — gentle ping: this is the 4th removal in the #23080 sweep; the first three (#23129, #23131, #23132) all landed today. Branch is up to date with upstream/main; commit 8b8e5f8 is ready for review. cargo-semver-checks should not need to bump since this is the only public-function removal in the datasource module on the branch. If you'd like me to rebase onto a recent main commit, let me know.

[Dodothereal]

Friendly nudge — this is a zero-caller pure-removal that unblocks another cleanup in #23080 series. Ready when a maintainer can approve CI / merge. (Same for #23135 right behind it.)

[alamb]

Friendly nudge — this is a zero-caller pure-removal that unblocks another cleanup in #23080 series. Ready when a maintainer can approve CI / merge. (Same for #23135 right behind it.)

thanks @Dodothereal -- we are working on it -- just never enough reviewer bandwidth unfortunately

[github-actions]

Thank you for opening this pull request!

Reviewer note: cargo-semver-checks reported the current version number is not SemVer-compatible with the changes in this pull request (compared against the base branch).

Details

     Cloning apache/main
    Building datafusion-datasource v54.0.0 (current)
       Built [  37.460s] (current)
     Parsing datafusion-datasource v54.0.0 (current)
      Parsed [   0.033s] (current)
    Building datafusion-datasource v54.0.0 (baseline)
       Built [  36.218s] (baseline)
     Parsing datafusion-datasource v54.0.0 (baseline)
      Parsed [   0.035s] (baseline)
    Checking datafusion-datasource v54.0.0 -> v54.0.0 (no change; assume patch)
     Checked [   0.386s] 223 checks: 220 pass, 3 fail, 0 warn, 30 skip

--- failure function_missing: pub fn removed or renamed ---

Description:
A publicly-visible function cannot be imported by its prior path. A `pub use` may have been removed, or the function itself may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.48.0/src/lints/function_missing.ron

Failed in:
  function datafusion_datasource::add_row_stats, previously in file /home/runner/work/datafusion/datafusion/target/semver-checks/git-apache_main/668f342273aa5c7408eced53df4a09f150f4afad/datafusion/datasource/src/statistics.rs:545

--- failure inherent_method_missing: pub method removed or renamed ---

Description:
A publicly-visible method or associated fn is no longer available under its prior name. It may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.48.0/src/lints/inherent_method_missing.ron

Failed in:
  FileScanConfigBuilder::with_output_partitioning, previously in file /home/runner/work/datafusion/datafusion/target/semver-checks/git-apache_main/668f342273aa5c7408eced53df4a09f150f4afad/datafusion/datasource/src/file_scan_config/mod.rs:479

--- failure struct_pub_field_missing: pub struct's pub field removed or renamed ---

Description:
A publicly-visible struct has at least one public field that is no longer available under its prior name. It may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.48.0/src/lints/struct_pub_field_missing.ron

Failed in:
  field output_partitioning of struct FileScanConfig, previously in file /home/runner/work/datafusion/datafusion/target/semver-checks/git-apache_main/668f342273aa5c7408eced53df4a09f150f4afad/datafusion/datasource/src/file_scan_config/mod.rs:218

     Summary semver requires new major version: 3 major and 0 minor checks failed
    Finished [  75.525s] datafusion-datasource