[master] f89e900fa vtc: Skip tests when diff(1) or cmp(1) are missing

[Dridi Boukelmoune]

commit f89e900fa2f35ec04605c3245e2ea48e43f721d9
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Tue Jul 19 08:48:00 2022 +0200

    vtc: Skip tests when diff(1) or cmp(1) are missing
    
    Some of the container images in our continuous integration are stripped
    of those commands.

diff --git a/bin/varnishtest/tests/e00003.vtc b/bin/varnishtest/tests/e00003.vtc
index 96bd91b32..e9906163e 100644
--- a/bin/varnishtest/tests/e00003.vtc
+++ b/bin/varnishtest/tests/e00003.vtc
@@ -1,5 +1,7 @@
 varnishtest "ESI include"
 
+feature cmd "command -v diff"
+
 server s1 {
 	rxreq
 	expect req.http.esi0 == "foo"
diff --git a/bin/varnishtest/tests/u00001.vtc b/bin/varnishtest/tests/u00001.vtc
index d2e7e34ab..0b5bf125b 100644
--- a/bin/varnishtest/tests/u00001.vtc
+++ b/bin/varnishtest/tests/u00001.vtc
@@ -1,5 +1,6 @@
 varnishtest "trivial run of varnishadm in script mode"
 
+feature cmd "command -v diff"
 feature cmd "python3 -c 'import json'"
 
 varnish v1 -vcl {backend be none;} -start
diff --git a/bin/varnishtest/tests/u00005.vtc b/bin/varnishtest/tests/u00005.vtc
index 0ffe02465..7e22b22e3 100644
--- a/bin/varnishtest/tests/u00005.vtc
+++ b/bin/varnishtest/tests/u00005.vtc
@@ -1,5 +1,7 @@
 varnishtest "varnishstat coverage"
 
+feature cmd "command -v cmp"
+
 server s1 {
 	rxreq
 	txresp