fix(test): Fix flaky tests caused by SentryOptions.activate

[adinauer]

#skip-changelog

📜 Description

Introduces NonOverridableNoOpSentryExecutorService in test support and uses it in SentryTest instead of NoOpSentryExecutorService.getInstance().

NoOpSentryExecutorService.getInstance() is a sentinel value that SentryOptions.activate() detects and replaces with a real executor service, which causes flaky test behavior when tests expect the executor to remain a no-op.

💡 Motivation and Context

Tests in SentryTest that set the executor service to NoOpSentryExecutorService.getInstance() became flaky after the introduction of SentryOptions.activate, which overrides sentinel no-op values. The new NonOverridableNoOpSentryExecutorService is a plain no-op implementation that is not recognized as a sentinel and therefore not replaced.

💚 How did you test it?

Verified the previously flaky tests now pass consistently.

📝 Checklist

• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

🔮 Next steps

None.

[github-actions]

Semver Impact of This PR

🟢 Patch (bug fixes)

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[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	315.75 ms	383.40 ms	67.65 ms
Size	1.58 MiB	2.29 MiB	720.88 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
e59e22a	329.74 ms	383.31 ms	53.57 ms
fc5ccaf	270.49 ms	363.90 ms	93.41 ms
d15471f	361.89 ms	378.07 ms	16.18 ms
d15471f	322.58 ms	396.08 ms	73.50 ms
abfcc92	304.04 ms	370.33 ms	66.29 ms
91bb874	310.68 ms	359.24 ms	48.56 ms
ab8a72d	316.24 ms	356.38 ms	40.14 ms
d15471f	286.65 ms	314.68 ms	28.03 ms
6727e14	337.22 ms	373.94 ms	36.71 ms
f064536	329.00 ms	395.62 ms	66.62 ms

App size

Revision	Plain	With Sentry	Diff
e59e22a	1.58 MiB	2.20 MiB	635.34 KiB
fc5ccaf	1.58 MiB	2.13 MiB	557.54 KiB
d15471f	1.58 MiB	2.13 MiB	559.54 KiB
d15471f	1.58 MiB	2.13 MiB	559.54 KiB
abfcc92	1.58 MiB	2.13 MiB	557.31 KiB
91bb874	1.58 MiB	2.13 MiB	559.07 KiB
ab8a72d	1.58 MiB	2.12 MiB	551.55 KiB
d15471f	1.58 MiB	2.13 MiB	559.54 KiB
6727e14	1.58 MiB	2.28 MiB	718.64 KiB
f064536	1.58 MiB	2.20 MiB	633.90 KiB