emacs-{28,29}: add deps to build PATH

Fixes #466 and #465

This kind of nullifies drawbacks of using standard env as it appends
critical stuff the beginning of PATH (e.g. prepends) and still allows
us to access it later to bake it in Emacs.app/Info.plist file.

Formula/emacs-plus@28.rb

@@ -34,6 +34,9 @@ class EmacsPlusAT28 < EmacsBase
   depends_on "make" => :build
   depends_on "autoconf" => :build
   depends_on "gnu-sed" => :build
+  depends_on "gnu-tar" => :build
+  depends_on "awk" => :build
+  depends_on "coreutils" => :build
   depends_on "pkg-config" => :build
   depends_on "texinfo" => :build
   depends_on "gnutls"
@@ -89,6 +92,13 @@ class EmacsPlusAT28 < EmacsBase
   #
 
   def install
+    # Expand PATH to include all dependencies and Superenv.bin as
+    # dependencies can override standard tools.
+    path = PATH.new()
+    path.append(deps.map { |dep| dep.to_formula.opt_bin })
+    path.append(ENV['PATH'])
+    ENV['PATH'] = path.existing
+
     args = %W[
       --disable-dependency-tracking
       --disable-silent-rules

Formula/emacs-plus@29.rb

@@ -27,6 +27,9 @@ class EmacsPlusAT29 < EmacsBase
   depends_on "make" => :build
   depends_on "autoconf" => :build
   depends_on "gnu-sed" => :build
+  depends_on "gnu-tar" => :build
+  depends_on "awk" => :build
+  depends_on "coreutils" => :build
   depends_on "pkg-config" => :build
   depends_on "texinfo" => :build
   depends_on "gnutls"
@@ -86,6 +89,13 @@ class EmacsPlusAT29 < EmacsBase
   #
 
   def install
+    # Expand PATH to include all dependencies and Superenv.bin as
+    # dependencies can override standard tools.
+    path = PATH.new()
+    path.append(deps.map { |dep| dep.to_formula.opt_bin })
+    path.append(ENV['PATH'])
+    ENV['PATH'] = path.existing
+
     args = %W[
       --disable-dependency-tracking
       --disable-silent-rules