upgrade: more liberal formula upgrade changes.

Download the bottle manifests for the potential formulae we are going to
upgrade and, if they are have all their `runtime_dependencies` versions
currently met, don't try to download the bottle or upgrade the formula.

Library/Homebrew/formula_installer.rb

@@ -31,6 +31,7 @@ class FormulaInstaller
   extend Predicable
 
   attr_reader :formula
+  attr_reader :bottle_tab_runtime_dependencies
 
   attr_accessor :options, :link_keg
 
@@ -96,7 +97,7 @@ def initialize(
     @requirement_messages = []
     @poured_bottle = false
     @start_time = nil
-    @bottle_tab_runtime_dependencies = {}
+    @bottle_tab_runtime_dependencies = {}.freeze
 
     # Take the original formula instance, which might have been swapped from an API instance to a source instance
     @formula = previously_fetched_formula if previously_fetched_formula

Library/Homebrew/upgrade.rb

@@ -22,6 +22,7 @@ def upgrade_formulae(
       installed_on_request: false,
       force_bottle: false,
       build_from_source_formulae: [],
+      dependents: false,
       interactive: false,
       keep_tmp: false,
       debug_symbols: false,
@@ -70,6 +71,20 @@ def upgrade_formulae(
           )
           unless dry_run
             fi.prelude
+
+            # Don't need to install this bottle if all the runtime dependencies
+            # are already satisfied.
+            next if dependents && fi.bottle_tab_runtime_dependencies.presence&.none? do |dependency, hash|
+              installed_version = begin
+                Formula[dependency].any_installed_version
+              rescue FormulaUnavailableError
+                nil
+              end
+              next true unless installed_version
+
+              Version.new(hash["version"]) > installed_version.version
+            end
+
             fi.fetch
           end
           fi
@@ -336,6 +351,7 @@ def check_installed_dependents(
           installed_on_request:       installed_on_request,
           force_bottle:               force_bottle,
           build_from_source_formulae: build_from_source_formulae,
+          dependents:                 true,
           interactive:                interactive,
           keep_tmp:                   keep_tmp,
           debug_symbols:              debug_symbols,