tidy: assume all files are modified in CI

Author: lolbinarycat

src/tools/tidy/src/lib.rs

@@ -126,6 +126,10 @@ pub fn git_diff<S: AsRef<OsStr>>(base_commit: &str, extra_arg: S) -> Option<Stri
 
 /// Returns true if any modified file matches the predicate, if we are in CI, or if unable to list modified files.
 pub fn files_modified(ci_info: &CiInfo, pred: impl Fn(&str) -> bool) -> bool {
+    if CiEnv::is_ci() {
+        // assume everything is modified on CI because we really don't want false positives there.
+        return true;
+    }
     let Some(base_commit) = &ci_info.base_commit else {
         eprintln!("No base commit, assuming all files are modified");
         return true;