fix(HashCommandLinter): remove unnecessary, broken workaround for tes…

…ts (#20529)

The old workaround for `test` is wrong on two accounts.

1. The test directory is now called `MathlibTest`, not `test`.
2. With the weak-option settings that mathlib uses, the test files are all already opt-in for the linters anyways.

Mathlib/Tactic/Linter/HashCommandLinter.lean

@@ -65,12 +65,9 @@ This means that CI will eventually fail on `#`-commands, but does not stop it fr
 However, in order to avoid local clutter, when `warningAsError` is `false`, the linter
 logs a warning only for the `#`-commands that do not already emit a message. -/
 def hashCommandLinter : Linter where run := withSetOptionIn' fun stx => do
-  let mod := (← getMainModule).components
   if Linter.getLinterValue linter.hashCommand (← getOptions) &&
-    ((← get).messages.reportedPlusUnreported.isEmpty || warningAsError.get (← getOptions)) &&
-    -- we check that the module is either not in `test` or, is `test.HashCommandLinter`
-    (mod.getD 0 default != `test || (mod == [`test, `HashCommandLinter]))
-    then
+    ((← get).messages.reportedPlusUnreported.isEmpty || warningAsError.get (← getOptions))
+  then
     if let some sa := stx.getHead? then
       let a := sa.getAtomVal
       if (a.get ⟨0⟩ == '#' && ! allowed_commands.contains a) then