[improve][build] Upgrade slog to 0.10.0

[lhotari]

Motivation

slog 0.10.0 is a correctness and performance pass over the logging hot paths, relevant to how Pulsar uses it:

• Fixes stale-level races in the Log4j2 cached level scheme (generation and effective level packed into a single word, atomic generation bumps)
• Routes through AsyncLogger in full-async mode (AsyncLoggerContextSelector) instead of calling LoggerConfig directly, which silently ran appender I/O on the application thread
• Pools log events only when Log4j2 thread-locals are enabled, avoiding cross-contamination of records when AsyncLoggerConfig enqueues events by reference
• Guards the pooled event against reentrant logging (e.g. an attr supplier that logs)
• Performance: monotonic clock for timed(), touched-keys-only MDC save/restore in the SLF4J handler, flattened logger context (+14% throughput, −60% allocation on context-bearing events), no per-thread event pooling on virtual threads, interleaved attr array (80 → 64 B/op on the fluent path)

Release notes: https://github.com/merlimat/slog/releases/tag/v0.10.0

Modifications

• Bump slog from 0.9.9 to 0.10.0 in gradle/libs.versions.toml. This also upgrades the transitive slog 0.9.9 pulled in by bookkeeper-common-allocator 4.18.0 via the platform constraint.
• Update the bundled jar version in distribution/server/src/assemble/LICENSE.bin.txt and distribution/shell/src/assemble/LICENSE.bin.txt.

No code changes are needed; 0.10.0 has no API changes.

Verifying this change

• Make sure that the change passes the CI checks.

This change is a trivial dependency upgrade without any test coverage. Verified locally with ./gradlew sanityCheck (all modules' main and test sources compile) and checkBinaryLicense for the server and shell distributions.

Does this pull request potentially affect one of the following parts:

If the box was checked, please highlight the changes

• Dependencies (add or upgrade a dependency)
• The public API
• The schema
• The default values of configurations
• The threading model
• The binary protocol
• The REST endpoints
• The admin CLI options
• The metrics
• Anything that affects deployment