[ADD] support for Odoo 18.0 configuration

Add config/18.0/ with configuration files based on OCA standards:
- .pylintrc and .pylintrc-mandatory (valid-odoo-versions=18.0)
- .ruff.toml (Python linting)
- .pre-commit-config.yaml with updated hooks:
  - whool-init (new in 18.0)
  - oca-gen-external-dependencies (new in 18.0)
  - Updated prettier 3.x and eslint 9.x
- eslint.config.cjs and prettier.config.cjs (new flat config format)

Also move .eslintrc.yml and .prettierrc.yml to config/16.0/ since
18.0 uses the new CJS flat config format instead of YAML.

config/18.0/.ruff.toml

@@ -0,0 +1,31 @@
+
+target-version = "py310"
+fix = true
+
+[lint]
+extend-select = [
+    "B",
+    "C90",
+    "E501",  # line too long (default 88)
+    "I",  # isort
+    "UP",  # pyupgrade
+]
+extend-safe-fixes = ["UP008"]
+exclude = ["setup/*"]
+
+[format]
+exclude = ["setup/*"]
+
+[lint.per-file-ignores]
+"__init__.py" = ["F401", "I001"]  # ignore unused and unsorted imports in __init__.py
+"__manifest__.py" = ["B018"]  # useless expression
+
+[lint.isort]
+section-order = ["future", "standard-library", "third-party", "odoo", "odoo-addons", "first-party", "local-folder"]
+
+[lint.isort.sections]
+"odoo" = ["odoo"]
+"odoo-addons" = ["odoo.addons"]
+
+[lint.mccabe]
+max-complexity = 16