(PA-5849) Consistently use miniruby when native compiling ruby 3.2

Ruby's build process requires a "base" ruby. We also need an executable ruby
that can install gems into /opt/puppetlabs/puppet/lib.

Previously, native compilation used whatever system ruby happened to be present.
Since each distro ships a different ruby, our build process used everything from
ruby 2.7 to 3.1 and everything in between.

This inconsistency made it more likely for our rubygem components with native
extensions to fail to install.

It also meant bumping to ruby 3.3 in the future could fail because that version
requires base ruby 3.0 or later, but some system rubies are still 2.7.

Additionally, in the past we've made the mistake of using pl-ruby because we
thought we had to.

This commit ensures we use miniruby for all native compiles. Doing so eliminates
all of the issues mentioned.

When cross-compiling, we still have to use either system ruby or pl-ruby.

configs/components/ruby-3.2.3.rb

@@ -91,30 +91,40 @@
     special_flags += " CFLAGS='#{settings[:cflags]}' LDFLAGS='#{settings[:ldflags]}' CPPFLAGS='#{settings[:cppflags]}' "
   end
 
+  # Ruby's build process requires a "base" ruby and we need a ruby to install
+  # gems into the /opt/puppetlabs/puppet/lib directory.
+  #
+  # For cross-compiles, the base ruby must be executable on the host we're
+  # building on (usually Intel), not the arch we're building for (such as
+  # SPARC). This is usually pl-ruby.
+  #
+  # For native compiles, we don't want ruby's build process to use whatever ruby
+  # is in the PATH, as it's probably too old to build ruby 3.2. And we don't
+  # want to use/maintain pl-ruby if we don't have to. Instead set baseruby to
+  # "no" which will force ruby to build and use miniruby.
+  if platform.is_cross_compiled?
+    special_flags += " --with-baseruby=#{host_ruby} "
+  else
+    special_flags += " --with-baseruby=no "
+  end
+
   if platform.is_aix?
     # This normalizes the build string to something like AIX 7.1.0.0 rather
     # than AIX 7.1.0.2 or something
     special_flags += " --build=#{settings[:platform_triple]} "
-  elsif platform.is_cross_compiled? && platform.is_linux?
-    special_flags += " --with-baseruby=#{host_ruby} "
   elsif platform.is_cross_compiled? && platform.is_macos?
     # When the target arch is aarch64, ruby incorrectly selects the 'ucontext' coroutine
     # implementation instead of 'arm64', so specify 'amd64' explicitly
     # https://github.com/ruby/ruby/blob/c9c2245c0a25176072e02db9254f0e0c84c805cd/configure.ac#L2329-L2330
-    special_flags += " --with-baseruby=#{host_ruby} --with-coroutine=arm64 "
+    special_flags += " --with-coroutine=arm64 "
   elsif platform.is_solaris? && platform.architecture == "sparc"
-    if platform.is_cross_compiled?
-      special_flags += " --with-baseruby=#{host_ruby} "
-    else
+    unless platform.is_cross_compiled?
       # configure seems to enable dtrace because the executable is present,
       # explicitly disable it and don't enable it below
-      special_flags += " --with-baseruby=no --enable-dtrace=no "
+      special_flags += " --enable-dtrace=no "
     end
     special_flags += "--enable-close-fds-by-recvmsg-with-peek "
-  elsif platform.name =~ /el-6/ || platform.name =~ /sles-11-x86_64/
-    # Since we're not cross compiling, ignore old ruby versions that happen to be in the PATH
-    # and force ruby to build miniruby and use that to bootstrap the rest of the build
-    special_flags += " --with-baseruby=no "
+
   elsif platform.is_windows?
     # ruby's configure script guesses the build host is `cygwin`, because we're using
     # cygwin opensshd & bash. So mkmf will convert compiler paths, e.g. -IC:/... to