Update function2 wrap to 4.2.0 and patch_directory

And switch to wrap-git.

subprojects/.gitignore

@@ -3,3 +3,6 @@
 # The above pattern doesn't match submodules
 /tomlplusplus
 /vst3
+
+# And we obviously don't want to ignore our overlays
+!/function2-patch/*

subprojects/function2-patch/meson.build

@@ -0,0 +1,3 @@
+project('function2', 'cpp', version : '4.2.0')
+
+function2_dep = declare_dependency(include_directories : include_directories('include'))

subprojects/function2.wrap

@@ -1,11 +1,7 @@
-[wrap-file]
-directory = function2-4.1.0
+[wrap-git]
+url = https://github.com/Naios/function2.git
+# Tag 4.2.0
+revision = 02ca99831de59c7c3a4b834789260253cace0ced
+depth = 1
 
-source_url = https://github.com/Naios/function2/archive/4.1.0.tar.gz
-source_filename = function2-4.1.0.tar.gz
-source_hash = c3aaeaf93bf90c0f4505a18f1094b51fe28881ce202c3bf78ec4efb336c51981
-
-# TODO: Meson 0.55 added patch_directory, so we can just use that instead
-patch_url = file:./subprojects/function2-patch-4.1.0.tar.xz
-patch_filename = function2-patch-4.1.0.tar.xz
-patch_hash = 4b966afd862413ea1f3d96484e74401992ec958f1ee2b4cc161f3cb7c36fe7ba
+patch_directory = subprojects/function2-patch