ci: improve PHP built-in server diagnostics

[vitormattos]

Summary

Update the integration-test dependency lock to libresign/behat-builtin-extension v0.7.1 and make the Behat workflows collect richer PHP crash diagnostics on debug reruns.

Changes

• update tests/integration/composer.lock to libresign/nextcloud-behat v1.6.2 and libresign/behat-builtin-extension v0.7.1;
• keep normal Behat runs unchanged and non-verbose;
• on GitHub Actions debug reruns, install gdb and systemd-coredump so the extension can query available core dumps and generate native backtraces when possible;
• on failed debug reruns, list available core dumps;
• upload the preserved /tmp/behat-php-server-* diagnostic files as artifacts;
• apply the same diagnostics to MariaDB, MySQL, PostgreSQL and SQLite Behat workflows.

The existing BEHAT_VERBOSE="$RUNNER_DEBUG" behavior remains unchanged, so none of the extra diagnostics run during normal CI.

Dependency chain

libresign/nextcloud-behat v1.6.2 now requires libresign/behat-builtin-extension ^0.7.1. LibreSign is updated to both releases in the same integration-test lockfile.

Dependabot

Composer updates under /tests/integration are already monitored daily. GitHub currently applies a default 3-day cooldown to version updates, which explains why the freshly published nextcloud-behat v1.6.2 was not proposed immediately. This PR makes that behavior explicit while excluding internal libresign/* packages from the cooldown, so future LibreSign package releases can be considered on the next scheduled Dependabot run.

[vitormattos]

/backport to stable35

[vitormattos]

/backport to stable34

[vitormattos]

/backport to stable33

[backportbot-libresign]

The backport to stable33 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable33
git pull origin stable33

# Create the new backport branch
git checkout -b backport/8690/stable33

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick 2dede2e0 e6d0b241 cd21ed63 744205c6 d2f77edc e942ed7e b0149404

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/8690/stable33

Error: Failed to push branch backport/8690/stable33: To https://github.com/LibreSign/libresign.git
! [remote rejected] backport/8690/stable33 -> backport/8690/stable33 (refusing to allow a GitHub App to create or update workflow .github/workflows/behat-mariadb.yml without workflows permission)
error: failed to push some refs to 'https://github.com/LibreSign/libresign.git'

---

Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.

[backportbot-libresign]

The backport to stable34 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable34
git pull origin stable34

# Create the new backport branch
git checkout -b backport/8690/stable34

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick 2dede2e0 e6d0b241 cd21ed63 744205c6 d2f77edc e942ed7e b0149404

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/8690/stable34

Error: Failed to push branch backport/8690/stable34: To https://github.com/LibreSign/libresign.git
! [remote rejected] backport/8690/stable34 -> backport/8690/stable34 (refusing to allow a GitHub App to create or update workflow .github/workflows/behat-mariadb.yml without workflows permission)
error: failed to push some refs to 'https://github.com/LibreSign/libresign.git'

---

Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.

[backportbot-libresign]

The backport to stable35 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable35
git pull origin stable35

# Create the new backport branch
git checkout -b backport/8690/stable35

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick 2dede2e0 e6d0b241 cd21ed63 744205c6 d2f77edc e942ed7e b0149404

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/8690/stable35

Error: Failed to push branch backport/8690/stable35: To https://github.com/LibreSign/libresign.git
! [remote rejected] backport/8690/stable35 -> backport/8690/stable35 (refusing to allow a GitHub App to create or update workflow .github/workflows/behat-mariadb.yml without workflows permission)
error: failed to push some refs to 'https://github.com/LibreSign/libresign.git'

---

Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.