The patch "[v3,3/3] ethdev: Reject conflicting TX offloads configuration" [1]
applied to next-net is causing CI failures.
Specifically, the test_txoffload_queue test case in the rxtx_offload_test_plan
test plan fails.

The patch 3/3 depends on "[v3,1/3] testpmd: Do not enable mbuf fast release TX
offload by default" [2], which has not yet been applied to next-net, and a
modification of the test plan related to this patch 1/3.

The required modifications to the "rxtx_offload_test_plan.rst" test plan are
described below.

## Are notes describing the modification, and should be omitted.

[1]:
https://patchwork.dpdk.org/project/dpdk/patch/20250803194218.683318-3-mb@smartsharesystems.com/
[2]:
https://patchwork.dpdk.org/project/dpdk/patch/20250803194218.683318-1-mb@smartsharesystems.com/


Test case: Intel® Ethernet 700 Series Tx offload per-queue setting
==================================================================

1. Start testpmd and get the tx_offload capability and configuration::

    ./<build_target>/app/dpdk-testpmd -c f -n 4 -- -i --rxq=4 --txq=4
    testpmd> show port 0 tx_offload capabilities
    Tx Offloading Capabilities of port 0 :
      Per Queue : MBUF_FAST_FREE
## MBUF_FAST_FREE is also supported per port (unrelated change)
-      Per Port  : VLAN_INSERT IPV4_CKSUM UDP_CKSUM TCP_CKSUM SCTP_CKSUM
TCP_TSO OUTER_IPV4_CKSUM QINQ_INSERT VXLAN_TNL_TSO GRE_TNL_TSO IPIP_TNL_TSO
GENEVE_TNL_TSO MULTI_SEGS
+      Per Port  : VLAN_INSERT IPV4_CKSUM UDP_CKSUM TCP_CKSUM SCTP_CKSUM
TCP_TSO OUTER_IPV4_CKSUM QINQ_INSERT VXLAN_TNL_TSO GRE_TNL_TSO IPIP_TNL_TSO
GENEVE_TNL_TSO MULTI_SEGS MBUF_FAST_FREE
    testpmd> show port 0 tx_offload configuration
    Tx Offloading Configuration of port 0 :
## The updated testpmd does not enable MBUF_FAST_FREE per default
-      Port : MBUF_FAST_FREE
+      Port :
      Queue[ 0] :
      Queue[ 1] :
      Queue[ 2] :
      Queue[ 3] :

## This is now the default state, so this test item has been moved to the end.
-2. Disable mbuf_fast_free per_port::
-
-    testpmd> port stop 0
-    testpmd> port config 0 tx_offload mbuf_fast_free off
-    testpmd> port start 0
-    testpmd> show port 0 tx_offload configuration
-    Tx Offloading Configuration of port 0 :
-      Port :
-      Queue[ 0] :
-      Queue[ 1] :
-      Queue[ 2] :
-      Queue[ 3] :
-
## Renumbered.
-3. Enable mbuf_fast_free per_queue::
+2. Enable mbuf_fast_free per_queue::

## With the above test item moved, the port has not yet been started. No need
to stop it.
-    testpmd> port stop 0
    testpmd> port 0 txq 0 tx_offload mbuf_fast_free on
    testpmd> port 0 txq 1 tx_offload mbuf_fast_free on
    testpmd> port 0 txq 2 tx_offload mbuf_fast_free on
    testpmd> port 0 txq 3 tx_offload mbuf_fast_free on
    testpmd> port start 0
    testpmd> show port 0 tx_offload configuration
    Tx Offloading Configuration of port 0 :
      Port :
      Queue[ 0] : MBUF_FAST_FREE
      Queue[ 1] : MBUF_FAST_FREE
      Queue[ 2] : MBUF_FAST_FREE
      Queue[ 3] : MBUF_FAST_FREE
    testpmd> start

   The port fwd can be started normally.

## Renumbered.
-4. Disable mbuf_fast_free per_queue::
+3. Disable mbuf_fast_free per_queue::

    testpmd> port stop 0
    testpmd> port 0 txq 0 tx_offload mbuf_fast_free off
    testpmd> port 0 txq 1 tx_offload mbuf_fast_free off
    testpmd> port 0 txq 2 tx_offload mbuf_fast_free off
    testpmd> port 0 txq 3 tx_offload mbuf_fast_free off
    testpmd> port start 0
    testpmd> show port 0 tx_offload configuration
    Tx Offloading Configuration of port 0 :
      Port :
      Queue[ 0] :
      Queue[ 1] :
      Queue[ 2] :
      Queue[ 3] :

## Renumbered.
-5. Enable mbuf_fast_free per_port::
+4. Enable mbuf_fast_free per_port::

    testpmd> port stop 0
    testpmd> port config 0 tx_offload mbuf_fast_free on
    testpmd> port start 0
    testpmd> show port 0 tx_offload configuration
    Tx Offloading Configuration of port 0 :
      Port : MBUF_FAST_FREE
      Queue[ 0] : MBUF_FAST_FREE
      Queue[ 1] : MBUF_FAST_FREE
      Queue[ 2] : MBUF_FAST_FREE
      Queue[ 3] : MBUF_FAST_FREE
    testpmd> start

   The port fwd can be started normally.

## Test item moved from above to here, and renumbered.
+5. Disable mbuf_fast_free per_port::
+
+    testpmd> port stop 0
+    testpmd> port config 0 tx_offload mbuf_fast_free off
+    testpmd> port start 0
+    testpmd> show port 0 tx_offload configuration
+    Tx Offloading Configuration of port 0 :
+      Port :
+      Queue[ 0] :
+      Queue[ 1] :
+      Queue[ 2] :
+      Queue[ 3] :
+
   Note 1: there is no tx_offload per_queue parameter in ixgbe driver,
   so this case is just only for i40e.