zuul: don't run puppet jobs when only patching requirements.txt

requirements.txt is only useful for reno jobs, we shouldn't run any
Puppet job when touching this file.

Change-Id: Ic7cb50b32ea947933ab11b0970904e7f1f226d66

.zuul.yaml

@@ -62,6 +62,7 @@
       - ^metadata.json$
       - ^releasenotes/.*$
       - ^spec/.*$
+      - ^requirements.txt$
       - ^test-requirements.txt$
     roles:
       - zuul: openstack-infra/zuul-jobs
@@ -314,6 +315,7 @@
       - ^etc/.*$
       - ^metadata.json$
       - ^releasenotes/.*$
+      - ^requirements.txt$
       - ^test-requirements.txt$
 
 - job:
@@ -327,6 +329,7 @@
       - ^etc/.*$
       - ^metadata.json$
       - ^releasenotes/.*$
+      - ^requirements.txt$
       - ^test-requirements.txt$
 
 - job:
@@ -348,6 +351,7 @@
       - ^etc/.*$
       - ^metadata.json$
       - ^releasenotes/.*$
+      - ^requirements.txt$
       - ^test-requirements.txt$
       - ^spec/acceptance/.*$
 
@@ -405,6 +409,7 @@
       - ^.*\.md$
       - ^spec/unit/.*$
       - ^spec/classes/.*$
+      - ^requirements.txt$
       - ^test-requirements.txt$
 
 - job: