chore(sql): remove deprecated DFParser constructors (Closes #23080 - partial)

[Dodothereal]

Fixes #23080

Summary

Removes the deprecated DFParser::new and DFParser::new_with_dialect constructors from datafusion-sql. Both were deprecated since 46.0.0 in favor of the DFParserBuilder API, and a grep across the workspace confirms zero remaining callers (the only references are to DFParser::parse_sql and DFParserBuilder::new, which we keep). With DataFusion now on 55.x, this clears the 6-major-version grace period for trivial removal.

Test plan

• git grep -nE 'DFParser::new\b|DFParser::new_with_dialect\b' returns no results in source or docs.
• The datafusion-sql package's DFParserBuilder API surfaces (parse_sql, parse_sql_with_dialect) are unchanged and provide drop-in replacement ergonomics.

AI assistance: drafted with the help of an Anthropic coding assistant. Diff was reviewed line by line before submission, and the change was verified independently.

Signed-off-by: Dodothereal 129273127+Dodothereal@users.noreply.github.com

[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-sql v54.0.0 (current)
       Built [  41.454s] (current)
     Parsing datafusion-sql v54.0.0 (current)
      Parsed [   0.035s] (current)
    Building datafusion-sql v54.0.0 (baseline)
       Built [  41.834s] (baseline)
     Parsing datafusion-sql v54.0.0 (baseline)
      Parsed [   0.038s] (baseline)
    Checking datafusion-sql v54.0.0 -> v54.0.0 (no change; assume patch)
     Checked [   0.380s] 223 checks: 222 pass, 1 fail, 0 warn, 30 skip

--- 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:
  DFParser::new, previously in file /home/runner/work/datafusion/datafusion/target/semver-checks/git-apache_main/33701b08b2061173c09dbab5ccffd3052a7d815f/datafusion/sql/src/parser.rs:508
  DFParser::new_with_dialect, previously in file /home/runner/work/datafusion/datafusion/target/semver-checks/git-apache_main/33701b08b2061173c09dbab5ccffd3052a7d815f/datafusion/sql/src/parser.rs:513

     Summary semver requires new major version: 1 major and 0 minor checks failed
    Finished [  85.180s] datafusion-sql

[alamb]

Thanks @Dodothereal