tests: use net prefix for prometheus tests

Prefix prometheus tests with net.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

tests/net/lib/prometheus/collector/testcase.yaml

@@ -1,6 +1,6 @@
 tests:
   # section.subsection
-  prometheus.collector:
+  net.prometheus.collector:
     depends_on: netif
     integration_platforms:
       - native_sim

tests/net/lib/prometheus/counter/testcase.yaml

@@ -1,6 +1,6 @@
 tests:
   # section.subsection
-  prometheus.counter:
+  net.prometheus.counter:
     depends_on: netif
     integration_platforms:
       - native_sim

tests/net/lib/prometheus/formatter/testcase.yaml

@@ -1,6 +1,6 @@
 tests:
   # section.subsection
-  prometheus.formatter:
+  net.prometheus.formatter:
     depends_on: netif
     integration_platforms:
       - native_sim

tests/net/lib/prometheus/gauge/testcase.yaml

@@ -1,6 +1,6 @@
 tests:
   # section.subsection
-  prometheus.gauge:
+  net.prometheus.gauge:
     depends_on: netif
     integration_platforms:
       - native_sim

tests/net/lib/prometheus/histogram/testcase.yaml

@@ -1,6 +1,6 @@
 tests:
   # section.subsection
-  prometheus.histogram:
+  net.prometheus.histogram:
     depends_on: netif
     integration_platforms:
       - native_sim

tests/net/lib/prometheus/summary/testcase.yaml

@@ -1,6 +1,6 @@
 tests:
   # section.subsection
-  prometheus.summary:
+  net.prometheus.summary:
     depends_on: netif
     integration_platforms:
       - native_sim