build/linux: Make json-c .patch self-contained in the Flatpak manifest

build/linux/flatpak/org.gimp.GIMP-nightly.json

@@ -431,9 +431,9 @@
                             }
                         },
                         {
-                            "type": "patch",
-                            "paths": [
-                                "patches/0001-Allow-build-with-cmake-4.0.0.patch"
+                            "type": "shell",
+                            "commands": [
+                                "perl -i -pe 'BEGIN{$m=0} $m=1 if s/cmake_minimum_required\\(VERSION 2\\.8\\)/cmake_minimum_required(VERSION 3.9...3.12)/; END{ if(!$m){ warn \"Patch failed on $ARGV\\n\"; exit 1 } }' apps/CMakeLists.txt"
                             ]
                         }
                     ],

build/linux/flatpak/patches/0001-Allow-build-with-cmake-4.0.0.patch

@@ -1,24 +0,0 @@
-From 42864e12b0d7af01b1cf989d6da9e9a4477775a1 Mon Sep 17 00:00:00 2001
-From: Rudi Heitbaum <rudi@heitbaum.com>
-Date: Fri, 28 Mar 2025 23:14:48 +1100
-Subject: [PATCH] Allow build with cmake 4.0.0
-
-Update the min version to match parent CMakeLists.txt 3.9...3.12
----
- apps/CMakeLists.txt | 2 +-
- 1 file changed, 1 insertion(+), 1 deletion(-)
-
-diff --git a/apps/CMakeLists.txt b/apps/CMakeLists.txt
-index f7c9dec..ef2271d 100644
---- a/apps/CMakeLists.txt
-+++ b/apps/CMakeLists.txt
-@@ -1,5 +1,5 @@
- 
--cmake_minimum_required(VERSION 2.8)  # see ../CMakeLists.txt for why 2.8
-+cmake_minimum_required(VERSION 3.9...3.12)
- 
- if(POLICY CMP0075)
-     cmake_policy(SET CMP0075 NEW)
--- 
-2.49.0.windows.1
-