Don't use bash in build; from sthen@/i3-mousedrag

x11/i3-gaps/patches/patch-meson_build

@@ -0,0 +1,14 @@
+$OpenBSD: patch-meson_build,v 1.1 2021/02/13 10:51:01 rsadowski Exp $
+
+Index: meson.build
+--- meson.build.orig
++++ meson.build
+@@ -598,7 +598,7 @@ install_headers(
+ # because configure_file strips the backslash in e.g. \@display,
+ # resulting in @display, breaking our Perl code:
+ # https://github.com/mesonbuild/meson/issues/7165
+-bash = find_program('bash')
++bash = find_program('sh')
+ replace_dirs = [
+   bash, '-c',  # Use bash to capture output and mark as executable
+   'sed -e \'s,@abs_top_builddir@,'