Change default for target-version option

crates/ruff_linter/src/rules/pyupgrade/rules/outdated_version_block.rs

@@ -237,11 +237,11 @@ fn version_always_less_than(
             };
 
             Ok(if or_equal {
-                // Ex) `sys.version_info <= 3.9`. If Python 3.9 is the minimum supported version,
+                // Ex) `sys.version_info <= 3.8`. If Python 3.8 is the minimum supported version,
                 // the condition won't always evaluate to `false`, so we want to return `false`.
                 if_minor < py_minor
             } else {
-                // Ex) `sys.version_info < 3.9`. If Python 3.9 is the minimum supported version,
+                // Ex) `sys.version_info < 3.8`. If Python 3.8 is the minimum supported version,
                 // the condition _will_ always evaluate to `false`, so we want to return `true`.
                 if_minor <= py_minor
             })

crates/ruff_workspace/src/options.rs

@@ -322,8 +322,8 @@ pub struct Options {
     /// file than it would for an equivalent runtime file with the same target
     /// version.
     #[option(
-        default = r#""py38""#,
-        value_type = r#""py37" | "py38" | "py39" | "py310" | "py311" | "py312""#,
+        default = r#""py39""#,
+        value_type = r#""py37" | "py38" | "py39" | "py310" | "py311" | "py312" | "py313""#,
         example = r#"
             # Always generate Python 3.7-compatible code.
             target-version = "py37"

docs/configuration.md

@@ -129,8 +129,8 @@ If left unspecified, Ruff's default configuration is equivalent to:
     line-length = 88
     indent-width = 4
 
-    # Assume Python 3.8
-    target-version = "py38"
+    # Assume Python 3.9
+    target-version = "py39"
 
     [lint]
     # Enable Pyflakes (`F`) and a subset of the pycodestyle (`E`)  codes by default.