Add typing for environment stats and LRUCache

[marcotc]

What does this PR do?

Small type improvements for environment stat modules and LRUCache:

• Environment::Socket#hostname: untyped → ::String
• Environment::VMCache#available?: untyped → bool?
• Environment::YJIT#available?: untyped → bool?
• Utils::LRUCache: @store, [], []= use any (intentionally generic key-value cache)

How to test the change?

bundle exec steep check lib/datadog/core/utils/lru_cache.rb

Changelog

None.

[github-actions]

👋 Hey @marcotc, please fill "Change log entry" section in the pull request description.

If changes need to be present in CHANGELOG.md you can state it this way

**Change log entry**

Yes. A brief summary to be placed into the CHANGELOG.md

(possible answers Yes/Yep/Yeah)

Or you can opt out like that

**Change log entry**

None.

(possible answers No/Nope/None)

^{Visited at: 2026-03-13 20:24:43 UTC}

[github-actions]

Typing analysis

Note: Ignored files are excluded from the next sections.

Untyped methods

This PR clears 2 untyped methods. It increases the percentage of typed methods from 61.14% to 61.24% (+0.1%).

Untyped methods (+0-2)

✅ Cleared:

sig/datadog/core/utils/lru_cache.rbs:13
└── def []: (untyped key) -> untyped?
sig/datadog/core/utils/lru_cache.rbs:15
└── def []=: (untyped key, untyped value) -> untyped

Untyped other declarations

This PR clears 1 partially typed other declaration. It increases the percentage of typed other declarations from 77.13% to 77.19% (+0.06%).

Partially typed other declarations (+0-1)

✅ Cleared:

sig/datadog/core/utils/lru_cache.rbs:7
└── @store: ::Hash[untyped, untyped]

[datadog-datadog-prod-us1-2]

✅ Tests

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 95.14% (-0.02%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: db9374d | Docs | Datadog PR Page | Was this helpful? React with 👍/👎 or give us feedback!}