guix: remove test-security/symbol-check scripts

These scripts are becoming more of nuisance, than a value-add;
particularly since we've been building releases using Guix. Adding new
(release bin) tests can be harder, because it requires constructing a
failing test, which is becoming less easy e.g trying to disable a
feature or protection that has been built into the compiler/toolchain by
default.

In the pre-Guix days, these were valuable to sanity-check the environment,
because we were pulling that pre-built from Ubuntu, with little control.
At this point, it's less clear what these scripts are (sanity) checking.

Note that these also weren't completely ported to CMake (#31698), see
also #31715 which contains other fixes that would be needed for these
test-tests, to accomodate future changes.

contrib/devtools/README.md

@@ -115,8 +115,8 @@ example:
 BUILDDIR=$PWD/build contrib/devtools/gen-bitcoin-conf.sh
 ```
 
-security-check.py and test-security-check.py
-============================================
+security-check.py
+=================
 
 Perform basic security checks on a series of executables.