Maintenance of code quality tools.

* Update pre-commit hooks to latest versions
* Remove obsolete or superseded sample codes from contrib/

Author: tturocy

.all-contributorsrc

@@ -34,7 +34,7 @@
         "ideas"
       ]
     },
-    {  
+    {
       "login": "edwardchalstrey1",
       "name": "Ed Chalstrey",
       "avatar_url": "https://avatars.githubusercontent.com/u/5486164?v=4",

.pre-commit-config.yaml

@@ -1,26 +1,26 @@
 repos:
 - repo: https://github.com/pre-commit/pre-commit-hooks
-  rev: v4.6.0
+  rev: v6.0.0
   hooks:
     - id: trailing-whitespace
     - id: end-of-file-fixer
     - id: check-yaml
     - id: check-added-large-files
 - repo: https://github.com/astral-sh/ruff-pre-commit
-  rev: v0.6.1
+  rev: v0.14.5
   hooks:
     - id: ruff
 - repo: https://github.com/pycqa/flake8
-  rev: 7.1.0
+  rev: 7.3.0
   hooks:
     - id: flake8
 - repo: https://github.com/MarcoGorelli/cython-lint
-  rev: v0.16.2
+  rev: v0.18.1
   hooks:
     - id: cython-lint
     - id: double-quote-cython-strings
 - repo: https://github.com/pre-commit/mirrors-clang-format
-  rev: v17.0.6
+  rev: v21.1.5
   hooks:
     - id: clang-format
       files: ^src\/.*\.(c|cc|cpp|h|imp)$