jobs/master-builds,gerrit-verifications: fix node

Do not set a node for master-builds and gerrit-verifications to run on,
as this leads to needlessly blocking slots on the jenkins nodes.

Each of these jobs is a matrix job with a slave_axis. The matrix job
itself can run on the "builtin" node, as it practically doesn't cause
load - all it does is start other jobs in the matrix (even if there is
only one other job, which is the default). Jobs started in the matrix
job do run on a configured node already, as the slave_axis parameter is
set.

I've just noticed this problem because currently the raspberry pi nodes
are offline, and so the master-osmo-trx, master-osmo-pcu and other jobs
take up lots of build slots just to wait until the raspberry pi nodes
come online and an actual build can start.

Change-Id: I447dd152fcc942ec48d0bcfbadd496e879c882da

jobs/gerrit-verifications.yml

@@ -31,7 +31,6 @@
     # following default values can be overridden by each repo
     disabled: false
     concurrent: true
-    node: osmocom-gerrit
     # axes related defaults
     slave_axis: !!python/tuple [osmocom-gerrit]
     a1_name: a1
@@ -583,7 +582,6 @@
 - job-template:
     name: 'gerrit-{repos}-build'
     project-type: matrix
-    node: '{node}'
     concurrent: '{obj:concurrent}'
     disabled: '{obj:disabled}'
     retry-count: 3 # scm checkout

jobs/master-builds.yml

@@ -5,7 +5,6 @@
     # following default values can be overridden by each repo
     disabled: false
     concurrent: true
-    node: 'osmocom-master'
     # axes related defaults
     slave_axis: !!python/tuple [osmocom-master]
     a1_name: a1
@@ -295,8 +294,7 @@
           git_base_url: https://gitea.osmocom.org/satellite
           email: jenkins-notifications@lists.osmocom.org 246tnt@gmail.com
 
-      - osmo-gsm-manuals:
-          node: 'osmocom-master'
+      - osmo-gsm-manuals
 
       - osmo-gsm-tester:
           cmd: '{docker_run} {docker_img} {timeout_cmd} /build/contrib/jenkins-build-manuals.sh'
@@ -495,7 +493,6 @@
       sequential: '{obj:sequential}'
       combination-filter: |
         {obj:combination_filter}
-    node: '{obj:node}'
     axes:
       - axis:
           type: slave