Ports/gnuplot: Update to version 5.4.8

We also no longer build the tutorial, as that directory no longer
exists.

Ports/gnuplot/package.sh

@@ -1,10 +1,10 @@
 #!/usr/bin/env -S bash ../.port_include.sh
 port=gnuplot
-version=5.2.8
+version='5.4.8'
 useconfigure=true
 # Note: gnuplot's source code is hosted on SourceForge, but using the GitHub mirror makes downloading a versioned .tar.gz easier.
 files=(
-    "https://github.com/gnuplot/gnuplot/archive/${version}.tar.gz b55f591e2ad9d01ffca821f2f91ce781b481bb5dd602ce5188bfad3140f44ac0"
+    "https://github.com/gnuplot/gnuplot/archive/${version}.tar.gz 2b0c1841640b2e33f8421ac83cd91d972d8b0c6acf9753f16385d5eec8a61a73"
 )
 configopts=("--prefix=${SERENITY_INSTALL_ROOT}/usr/local" "--with-readline=builtin" "--without-latex")
 

Ports/gnuplot/patches/0001-Don-t-build-the-docs-and-the-demo.patch

@@ -10,18 +10,18 @@ Subject: [PATCH] Don't build the docs and the demo
  1 file changed, 4 insertions(+), 1 deletion(-)
 
 diff --git a/Makefile.am b/Makefile.am
-index 9241ce5..1e2f6c6 100644
+index 7e2c4008cda62e8b8e2959e4d2953722f6d350db..a8df6c0617210c7d7344052e3a34c56993232b33 100644
 --- a/Makefile.am
 +++ b/Makefile.am
 @@ -1,7 +1,10 @@
  ## Process this file with automake to produce Makefile.in -*-Makefile-*-
  AUTOMAKE_OPTIONS = foreign
  
--SUBDIRS = config m4 term src docs man demo tutorial share
+-SUBDIRS = config m4 term src docs man demo share
 +# Note: For the SerenityOS port of gnuplot, the following have been removed:
 +# docs - segfault during make :/
 +# demo - x86_64-pc-serenity-gcc: error: unrecognized command line option '-rdynamic'
-+SUBDIRS = config m4 term src man tutorial share
++SUBDIRS = config m4 term src man share
  
- EXTRA_DIST = BUGS Copyright FAQ.pdf GNUmakefile INSTALL INSTALL.gnu \
- Makefile.maint PATCHLEVEL PGPKEYS README RELEASE_NOTES \
+ EXTRA_DIST = BUGS Copyright FAQ.pdf INSTALL INSTALL.gnu \
+ PATCHLEVEL PGPKEYS README RELEASE_NOTES \