[lldb][test] Disable PIE for some API tests (#93808)

When PIE is enabled on a platform by default, these tests fail since the
`target variable` command can't read a global string variable value
before running an inferior process.

It fixes the following tests when built with clang on Ubuntu aarch64:
```
commands/target/basic/TestTargetCommand.py
lang/c/global_variables/TestGlobalVariables.py
lang/cpp/char8_t/TestCxxChar8_t.py
```