test: unset force_simradio so admin request pinning is exercised

The native test harness boots Portduino in simulated mode, and
wouldEncryptWithPKC() short-circuits to false whenever
portduino_config.force_simradio is set. noteOutgoingAdminRequest() derives its
pin from that predicate:

    keyValid = haveDestKey && wouldEncryptWithPKC(&p, p.channel, haveDestKey);

so under the harness no outgoing admin request is ever key-pinned, and
responseIsSolicited() admits a plaintext response to a PKC-pinned request.
test_pinned_request_keeps_its_key_after_an_unpinned_request and
test_request_to_keyed_node_pins_the_stored_key have therefore failed since
#11092 added them, on develop and on every branch that merges it.

Instrumenting the predicate shows every other term already satisfied
(haveDestKey=1, isFromUs=1, private_key=32, unicast, ADMIN_APP, channel
LongFast) with wouldEncryptWithPKC=0, leaving only the simradio guard.

Clear the flag in setUp so the fixture models a real device. Skipping PKC under
force_simradio is correct for a simulated radio - there is no PKC to pin - so
the predicate is left alone rather than relaxed to make a test pass. The only
sim-mode path in this suite is AdminModule's exit_simulator intercept, which no
test here exercises.

Native suite: 38 suites, 723/723 cases, no sanitizer findings.

test/test_admin_session_repro/test_main.cpp

@@ -21,6 +21,10 @@
 #include "support/MockMeshService.h"
 #include <cstring>
 
+#ifdef ARCH_PORTDUINO
+#include "platform/portduino/PortduinoGlue.h"
+#endif
+
 static constexpr NodeNum LOCAL_NODE = 0x0A0A0A0A;
 static constexpr NodeNum ADMIN_NODE = 0x0B0B0B0B;   // authorized admin, sends remote admin to us
 static constexpr NodeNum QUERIED_NODE = 0x0C0C0C0C; // a remote we send admin requests to
@@ -157,6 +161,14 @@ void setUp(void)
     nodeDB = mockNodeDB;
     myNodeInfo.my_node_num = LOCAL_NODE;
 
+#ifdef ARCH_PORTDUINO
+    // The native test harness boots Portduino in simulated mode, and wouldEncryptWithPKC()
+    // hard-disables PKC whenever force_simradio is set. Left true, no outgoing admin request is
+    // ever key-pinned, so the pinning tests below cannot exercise what they are asserting.
+    // Model a real (non-sim) device instead.
+    portduino_config.force_simradio = false;
+#endif
+
     config = meshtastic_LocalConfig_init_zero;
     // A real device always holds a private key; without one perhapsEncode never picks PKC.
     config.security.private_key.size = 32;