Merge branch 'selftests-bpf-migrate-a-few-bpftool-testing-scripts'

Merge branch 'selftests-bpf-migrate-a-few-bpftool-testing-scripts'

Alexis Lothoré says:

====================
selftests/bpf: migrate a few bpftool testing scripts

this is the v4 for some bpftool tests conversion. The new tests are
being integrated in test_progs so that they can be executed on each CI
run.

- First commit introduces a few dedicated helpers to execute bpftool
  commands, with or without retrieving the generated stdout output
- Second commit integrates test_bpftool_metadata.sh into test_progs
- Third commit integrates test_bpftool_map.sh into test_progs

Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com>
---
Changes in v4:
- Port missing map access test in bpftool_metadata
- Link to v3: https://lore.kernel.org/r/20260121-bpftool-tests-v3-0-368632f377e5@bootlin.com

Changes in v3:
- Drop commit reordering objects in Makefile
- Rebased series on ci/bpf-next_base to fix conflict
- Link to v2: https://lore.kernel.org/r/20260121-bpftool-tests-v2-0-64edb47e91ae@bootlin.com

Changes in v2:
- drop standalone runner in favor of test_progs
- Link to v1: https://lore.kernel.org/r/20260114-bpftool-tests-v1-0-cfab1cc9beaf@bootlin.com

====================

Link: https://patch.msgid.link/20260123-bpftool-tests-v4-0-a6653a7f28e7@bootlin.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>