Update Ghidra HEAD to commit 134f5394f (#423)

Bump Ghidra HEAD commit 134f5394f

Changed files:

```
M	Ghidra/Features/Decompiler/src/decompile/cpp/bitfield.cc
M	Ghidra/Features/Decompiler/src/decompile/cpp/bitfield.hh
M	Ghidra/Features/Decompiler/src/decompile/cpp/ruleaction.cc
```

Commit details:

```
[Commit 1/2]
Hash: e1a1dc14e98dc8db0f30b0602fd4ce1301361f2e
Date: 2026-05-27 22:20:55 +0000
Message: GP-6882 Check for free varnode in RuleDoubleSub

Files changed:
  M	Ghidra/Features/Decompiler/src/decompile/cpp/ruleaction.cc

[Commit 2/2]
Hash: 6e88715d8be92ebea52f297cf839127037d7f626
Date: 2026-05-19 22:17:50 +0000
Message: GP-6850 adjust handling of INDIRECT in BitFieldInsertTransform

Files changed:
  M	Ghidra/Features/Decompiler/src/decompile/cpp/bitfield.cc
  M	Ghidra/Features/Decompiler/src/decompile/cpp/bitfield.hh
```

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: auto-updater[bot]

src/setup-ghidra-source.cmake

@@ -55,7 +55,7 @@ if("${sleigh_RELEASE_TYPE}" STREQUAL "HEAD")
   # TODO: CMake only likes numeric characters in the version string....
   set(ghidra_head_version "12.2")
   set(ghidra_version "${ghidra_head_version}")
-  set(ghidra_head_git_tag "6e8d599d520e5bf42d556d8d2a4871744063a641")
+  set(ghidra_head_git_tag "134f5394fc3ef46a15a4a7b102bef28f96e2d491")
   set(ghidra_git_tag "${ghidra_head_git_tag}")
   set(ghidra_shallow FALSE)
   set(ghidra_patches