tests: lib: net_buf: move network buffer tests to tests/lib/net_buf

Move the network buffer tests to tests/lib/net_buf as their implementation
now lives outside of the networking subsystem.

Signed-off-by: Henrik Brix Andersen <henrik@brixandersen.dk>

MAINTAINERS.yml

@@ -2835,7 +2835,7 @@ Networking:
   tests:
     - net.socket
 
-"Networking: Buffers":
+"Networking Buffers":
   status: maintained
   maintainers:
     - jhedberg
@@ -2848,11 +2848,11 @@ Networking:
     - include/zephyr/net/buf.h
     - include/zephyr/net_buf.h
     - lib/net_buf/
-    - tests/net/buf/
+    - tests/lib/net_buf/
   labels:
     - "area: Networking Buffers"
   tests:
-    - net.buf
+    - libraries.net_buf
 
 "Networking: Connection Manager":
   status: maintained

tests/lib/net_buf/buf/testcase.yaml

@@ -0,0 +1,5 @@
+tests:
+  libraries.net_buf.buf:
+    min_ram: 16
+    tags:
+      - net_buf

tests/lib/net_buf/buf_simple/testcase.yaml

@@ -0,0 +1,6 @@
+common:
+  tags:
+    - net_buf
+tests:
+  libraries.net_buf.buf_simple:
+    type: unit

tests/net/buf/testcase.yaml

@@ -1,6 +0,0 @@
-tests:
-  net.buf:
-    min_ram: 16
-    tags:
-      - net
-      - buf

tests/net/buf_simple/testcase.yaml

@@ -1,7 +0,0 @@
-common:
-  tags:
-    - net
-    - buf
-tests:
-  net.buf_simple:
-    type: unit