Storages: Deprecated libclara for normal build (#10325)

[ti-chi-bot]

This is an automated cherry-pick of #10325

What problem does this PR solve?

Issue Number: close #10324

Problem Summary:

What is changed and how it works?

Storages: Deprecated libclara for normal build
  * Add `ENABLE_CLARA` and disable it by default in normal build
  * Exclude the files under `dbms/src/Storages/DeltaMerge/Index/FullTextIndex` when `ENABLE_CLARA` is disabled

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
  Both debug and release build in local env is success

# Debug build
>  ninja -j 32 tiflash gtests_dbms gtests_libcommon
>  ./dbms/src/Server/tiflash version
TiFlash
Release Version: v9.0.0-beta.2.pre-15-g33e88b3667
Edition:         Community
Git Commit Hash: 33e88b36675ec72288bda52b5c296e3f55789d43
Git Branch:      deprecated_clara
UTC Build Time:  2025-08-04 04:57:48
Enable Features: jemalloc sm4(GmSSL) mem-profiling failpoints avx2 avx512 unwind hnsw.l2=skylake hnsw.cosine=skylake vec.l2=skylake vec.cos=skylake
Profile:         DEBUG
Compiler:        clang++ 17.0.6

Raft Proxy
Git Commit Hash:   3e325b2b9b30e396c846bfeb97a690d070b84087
Git Commit Branch: HEAD
UTC Build Time:    ""   
Rust Version:      rustc 1.77.0-nightly (89e2160c4 2023-12-27)
Storage Engine:    tiflash
Prometheus Prefix: tiflash_proxy_
Profile:           debug
Enable Features:   external-jemalloc portable sse test-engine-kv-rocksdb test-engine-raft-raft-engine openssl-vendored

# Release build
> ninja -j 32 tiflash
>  ./dbms/src/Server/tiflash version
TiFlash
Release Version: v9.0.0-beta.2.pre-15-g33e88b3667
Edition:         Community
Git Commit Hash: 33e88b36675ec72288bda52b5c296e3f55789d43
Git Branch:      deprecated_clara
UTC Build Time:  2025-08-04 04:57:30
Enable Features: jemalloc sm4(GmSSL) mem-profiling avx2 avx512 unwind hnsw.l2=skylake hnsw.cosine=skylake vec.l2=skylake vec.cos=skylake
Profile:         RelWithDebInfo
Compiler:        clang++ 17.0.6

Raft Proxy
Git Commit Hash:   3e325b2b9b30e396c846bfeb97a690d070b84087
Git Commit Branch: HEAD
UTC Build Time:    ""   
Rust Version:      rustc 1.77.0-nightly (89e2160c4 2023-12-27)
Storage Engine:    tiflash
Prometheus Prefix: tiflash_proxy_
Profile:           release
Enable Features:   external-jemalloc portable sse test-engine-kv-rocksdb test-engine-raft-raft-engine openssl-vendored

• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

None

[ti-chi-bot]

This cherry pick PR is for a release branch and has not yet been approved by triage owners.
Adding the do-not-merge/cherry-pick-not-approved label.

To merge this cherry pick:

1. It must be approved by the approvers firstly.
2. AFTER it has been approved by approvers, please wait for the cherry-pick merging approval from triage owners.

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[ti-chi-bot]

@JaySon-Huang This PR has conflicts, I have hold it.
Please resolve them or ask others to resolve them, then comment /unhold to remove the hold label.

[ti-chi-bot]

@ti-chi-bot: ## If you want to know how to resolve it, please read the guide in TiDB Dev Guide.

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[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: JinheLin, Lloyd-Pottiger

The full list of commands accepted by this bot can be found here.

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Needs approval from an approver in each of these files:

• OWNERS [JinheLin,Lloyd-Pottiger]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-08-05 02:18:25.705837771 +0000 UTC m=+321015.848598936: ☑️ agreed by JinheLin.
• 2025-08-05 06:45:52.016276498 +0000 UTC m=+337062.159037663: ☑️ agreed by Lloyd-Pottiger.