science/pulseview: fix crash on startup when libcxx has asserts enabled

The program's code unlocks a mutex that it never locked.
When libcxx is built with debug (e.g., on stable branches) there is a
crash on an assert that pthread_mutex_unlock succeeds.

This change adds a patch for the problem.

PR:		282727
Approved by:	uzsolt

science/pulseview/files/patch-pv_data_decodesignal.cpp

@@ -0,0 +1,15 @@
+--- pv/data/decodesignal.cpp.orig	2020-03-31 23:41:18.000000000 +0300
++++ pv/data/decodesignal.cpp	2024-11-08 15:04:00.844432000 +0200
+@@ -251,11 +251,8 @@
+ 
+ void DecodeSignal::resume_decode()
+ {
+-	// Manual unlocking is done before notifying, to avoid waking up the
+-	// waiting thread only to block again (see notify_one for details)
+-	decode_pause_mutex_.unlock();
+-	decode_pause_cond_.notify_one();
+ 	decode_paused_ = false;
++	decode_pause_cond_.notify_one();
+ }
+ 
+ bool DecodeSignal::is_paused() const