Remove deprecated Local metadata server and config options

[pcholakov]

IMPORTANT: This should only be merged once we are ready to release 1.4.0

Something I've noticed is that we don't fail with an error if a value is specified for an enum-based property, which cannot be resolved to any particular variant - this was not introduced by this change but I was surprised to discover that e.g. # [metadata-client] type = "foo" just silently reverts to the default (e.g. replicated following this change).

Defaults are unchanged:

[metadata-server]
request-queue-length = 32
rocksdb-memory-budget = "29.2 MiB"
rocksdb-memory-ratio = 0.009999999776482582
rocksdb-disable-direct-io-for-reads = true
rocksdb-disable-direct-io-for-flush-and-compactions = true
rocksdb-disable-wal = false
rocksdb-disable-statistics = false
rocksdb-max-background-jobs = 14
rocksdb-compaction-readahead-size = "1.9 MiB"
rocksdb-statistics-level = "except-timers"
rocksdb-log-level = "error"
rocksdb-log-keep-file-num = 1
rocksdb-log-max-file-size = "61.0 MiB"
rocksdb-block-size = "64.0 KiB"
raft-election-tick = 10
raft-heartbeat-tick = 2
raft-tick-interval = "100ms"
status-update-interval = "5s"
log-trim-threshold = 1000

We still detect potential misconfiguration if a user runs the metadata-server role with one of the non-native client types:

2025-06-03T20:12:53.446686Z ERROR restate_server: Restate application failed error=Invalid configuration: Detected possible misconfiguration. This node runs a "local" metadata server but is configured to use the "object-store" metadata client. If you don't want to run a metadata server, remove the metadata-server role. If you want to use the Restate metadata store, then set metadata-client.type = "replicated" or leave it unset restate.error.code=None

[github-actions]

Test Results

  7 files  ±0    7 suites  ±0   4m 59s ⏱️ +8s
 54 tests ±0   53 ✅ ±0  1 💤 ±0  0 ❌ ±0 
223 runs  ±0  220 ✅ ±0  3 💤 ±0  0 ❌ ±0 

Results for commit c601f2e. ± Comparison against base commit f73e1f4.

♻️ This comment has been updated with latest results.

[pcholakov]

I believe we have equivalent coverage for the Raft Server path between the RocksDB durability layer and the Raft cluster chaos test; but let me know if you think there's value in porting these over to the Raft Server.

[pcholakov]

Moved to mod.rs.

[AhmedSoliman]

Wrong title?

[tillrohrmann]

This PR should be merged once we decide to release 1.4.0, right?

[pcholakov]

Wrong title?

Indeed it was! Sorry about that.

This PR should be merged once we decide to release 1.4.0, right?

Yes, definitely!