API Deprecate references to installation tool (#11275)

src/Core/BaseKernel.php

@@ -27,6 +27,7 @@
 use SilverStripe\View\ThemeManifest;
 use SilverStripe\View\ThemeResourceLoader;
 use Exception;
+use SilverStripe\Dev\Deprecation;
 
 /**
  * Simple Kernel container
@@ -308,10 +309,13 @@ protected function detectLegacyEnvironment()
      * If missing configuration, redirect to install.php if it exists.
      * Otherwise show a server error to the user.
      *
+     * @deprecated 5.3.0 Will be removed without equivalent functionality
+     *
      * @param string $msg Optional message to show to the user on an installed project (install.php missing).
      */
     protected function redirectToInstaller($msg = '')
     {
+        Deprecation::notice('5.3.0', 'Will be removed without equivalent functionality');
         // Error if installer not available
         if (!file_exists(Director::publicFolder() . '/install.php')) {
             throw new HTTPResponse_Exception(

src/Core/CoreKernel.php

@@ -7,6 +7,7 @@
 use SilverStripe\ORM\DB;
 use Exception;
 use LogicException;
+use SilverStripe\Dev\Deprecation;
 
 /**
  * Simple Kernel container
@@ -52,7 +53,7 @@ protected function validateDatabase()
             $msg = 'Silverstripe Framework requires a "database" key in DB::getConfig(). ' .
                 'Did you forget to set SS_DATABASE_NAME or SS_DATABASE_CHOOSE_NAME in your environment?';
             $this->detectLegacyEnvironment();
-            $this->redirectToInstaller($msg);
+            Deprecation::withNoReplacement(fn() => $this->redirectToInstaller($msg));
         }
     }