test(agc): disable the shader disk cache in agc_shader_memory_tests

[YatoVoid]

What

Fixes #6076.

The failure is not NVIDIA-specific. agc_shader_memory_tests uses the shader disk cache when it is run directly, because only the CTest registrations set ANYPS5_NO_SHADER_CACHE=1. The first direct run passes and writes tests/shader_cache. On every later run findOrCompileVariant loads the variants from that cache instead of building a resource program, so ResourcePrograms() is 0 and the layout pair check fails with "the second layout ignored the reuse switch". CI never sees it because CTest disables the cache.

main now sets ANYPS5_NO_SHADER_CACHE=1 before any test runs, as tests/Mesh.cpp already does, so a direct run behaves like the CTest one.

Tested

Arch Linux, GCC, Release, NVIDIA RTX 3050 Laptop (the test does not use the GPU).

• Before: with ANYPS5_SHADER_CACHE_DIR pointing at an empty directory, agc_shader_memory_tests --layout-pair passes on the first run and fails on the second and third with the message from the issue. With ANYPS5_NO_SHADER_CACHE=1 it passes every time.
• After: --layout-pair, --frontend-pair and the no-argument run pass repeatedly against the warm cache directory and from the default location; no shader_cache directory is created next to the binary.
• ctest -R 'agc_shader_(memory|bindless|srt_read_patching|frontend_pair|layout_pair)': 7/7 passed.
• python3 tools/check_conventions.py --base origin/main: passed.

Checklist

• Based on current main; no other open PR implements the same functions
• One topic per PR; follow-ups go in a new PR
• No comments in code except technical debt
• Unimplemented paths throw (NotImplemented_nid_no_patch); silent stubs are listed under Silent stubs in their library's technical debt file
• No notes, investigation .md files or images added to the repository (attach them to this PR)
• New third-party code is a submodule built from source
• Generic behaviour, not specific to one title
• Depends on: none
• Unblocks: none
• GPUs tested: n/a (test-only change; the test runs no GPU work)
• AI-assisted: no

[github-actions]

Some comparisons could not be completed because a pull request conflicts with the base branch. Review these shared files manually before concluding that there is no overlap.

Pull request	Shared files not compared
PR 1341	core/libs/prx/libSceAgcDriver/tests/ShaderMemory.cpp
PR 5371	core/libs/prx/libSceAgcDriver/tests/ShaderMemory.cpp
PR 5500	core/libs/prx/libSceAgcDriver/tests/ShaderMemory.cpp
PR 6177	core/libs/prx/libSceAgcDriver/tests/ShaderMemory.cpp
PR 6222	core/libs/prx/libSceAgcDriver/tests/ShaderMemory.cpp
PR 6232	core/libs/prx/libSceAgcDriver/tests/ShaderMemory.cpp
PR 6235	core/libs/prx/libSceAgcDriver/tests/ShaderMemory.cpp
PR 6412	core/libs/prx/libSceAgcDriver/tests/ShaderMemory.cpp
PR 6488	core/libs/prx/libSceAgcDriver/tests/ShaderMemory.cpp
PR 6503	core/libs/prx/libSceAgcDriver/tests/ShaderMemory.cpp
PR 6645	core/libs/prx/libSceAgcDriver/tests/ShaderMemory.cpp

[adriadam10]

Checked: ANYPS5_NO_SHADER_CACHE=1 is set before anything runs, same as tests/Mesh.cpp; agc_shader_memory passes in ctest and --layout-pair passes three consecutive direct runs sharing one cache dir. Merging.