formula_installer: don't always post_install.

We don't want to do so when building bottles or we can end up with some weird stuff being bottled unintentionally (and it'll run twice; once before bottling, once afterwards).

Fixes Homebrew/homebrew#34349.

Closes Homebrew/homebrew#34397.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Library/Homebrew/formula_installer.rb

@@ -395,7 +395,12 @@ class FormulaInstaller
     link(keg)
     fix_install_names(keg) if OS.mac?
 
-    post_install
+    if build_bottle?
+      ohai "Not running post_install as we're building a bottle"
+      puts "You can run it manually using `brew postinstall #{formula.name}`"
+    else
+      post_install
+    end
 
     ohai "Summary" if verbose? or show_summary_heading?
     puts summary