fix(ocr): main builds on Windows again: the executable check is its own function per platform (#7222)

Since Rust 1.100, clippy's needless_bool refused program_is_executable on Windows: with the
#[cfg(unix)] block gone it read if ... { return false; } true, and the Windows gate failed on
every main commit since 13 Nov 09:38. The check is now one expression with the platform part
in has_execute_permission; behaviour is unchanged on every platform.

crates/ocr/src/tesseract.rs

@@ -130,18 +130,22 @@ pub fn program_is_usable(program: &Path) -> bool {
 /// executable FILE (on Unix the executable bits must be set; elsewhere being a file is what
 /// the OS requires). A directory or a missing file is simply unavailable — never a panic.
 fn program_is_executable(program: &Path) -> bool {
-    if !program.is_absolute() || !program.is_file() {
-        return false;
-    }
-    #[cfg(unix)]
-    {
-        use std::os::unix::fs::PermissionsExt;
-        std::fs::metadata(program).is_ok_and(|m| m.permissions().mode() & 0o111 != 0)
-    }
-    #[cfg(not(unix))]
-    {
-        true
-    }
+    program.is_absolute() && program.is_file() && has_execute_permission(program)
+}
+
+/// Unix: an executable bit is set.
+#[cfg(unix)]
+fn has_execute_permission(program: &Path) -> bool {
+    use std::os::unix::fs::PermissionsExt;
+    std::fs::metadata(program).is_ok_and(|m| m.permissions().mode() & 0o111 != 0)
+}
+
+/// Elsewhere, being a file is what the OS requires. A function of its own: inlined above, the
+/// Windows build reduced to `if … { return false; } true`, which clippy's `needless_bool`
+/// refuses (Rust 1.100).
+#[cfg(not(unix))]
+fn has_execute_permission(_program: &Path) -> bool {
+    true
 }
 
 /// One row of Tesseract's TSV output. `level` 5 rows are the words; `conf` is −1 on the header