Remove deprecated configuration '--show-source` (#9814)

Co-authored-by: Micha Reiser <micha@reiser.io>
Fixes parts of https://github.com/astral-sh/ruff/issues/7650

ruff.schema.json

@@ -534,7 +534,7 @@
       "description": "The style in which violation messages should be formatted: `\"full\"` (shows source),`\"concise\"` (default), `\"grouped\"` (group messages by file), `\"json\"` (machine-readable), `\"junit\"` (machine-readable XML), `\"github\"` (GitHub Actions annotations), `\"gitlab\"` (GitLab CI code quality report), `\"pylint\"` (Pylint text format) or `\"azure\"` (Azure Pipeline logging commands).",
       "anyOf": [
         {
-          "$ref": "#/definitions/SerializationFormat"
+          "$ref": "#/definitions/OutputFormat"
         },
         {
           "type": "null"
@@ -670,14 +670,6 @@
         "null"
       ]
     },
-    "show-source": {
-      "description": "Whether to show source code snippets when reporting lint violations (overridden by the `--show-source` command-line flag).",
-      "deprecated": true,
-      "type": [
-        "boolean",
-        "null"
-      ]
-    },
     "src": {
       "description": "The directories to consider when resolving first- vs. third-party imports.\n\nAs an example: given a Python package structure like:\n\n```text my_project ├── pyproject.toml └── src └── my_package ├── __init__.py ├── foo.py └── bar.py ```\n\nThe `./src` directory should be included in the `src` option (e.g., `src = [\"src\"]`), such that when resolving imports, `my_package.foo` is considered a first-party import.\n\nWhen omitted, the `src` directory will typically default to the directory containing the nearest `pyproject.toml`, `ruff.toml`, or `.ruff.toml` file (the \"project root\"), unless a configuration file is explicitly provided (e.g., via the `--config` command-line flag).\n\nThis field supports globs. For example, if you have a series of Python packages in a `python_modules` directory, `src = [\"python_modules/*\"]` would expand to incorporate all of the packages in that directory. User home directory and environment variables will also be expanded.",
       "type": [
@@ -2301,6 +2293,24 @@
       },
       "additionalProperties": false
     },
+    "OutputFormat": {
+      "type": "string",
+      "enum": [
+        "text",
+        "concise",
+        "full",
+        "json",
+        "json-lines",
+        "junit",
+        "grouped",
+        "github",
+        "gitlab",
+        "pylint",
+        "rdjson",
+        "azure",
+        "sarif"
+      ]
+    },
     "ParametrizeNameType": {
       "type": "string",
       "enum": [
@@ -3939,24 +3949,6 @@
         "YTT303"
       ]
     },
-    "SerializationFormat": {
-      "type": "string",
-      "enum": [
-        "text",
-        "concise",
-        "full",
-        "json",
-        "json-lines",
-        "junit",
-        "grouped",
-        "github",
-        "gitlab",
-        "pylint",
-        "rdjson",
-        "azure",
-        "sarif"
-      ]
-    },
     "Strictness": {
       "oneOf": [
         {