ref: Convert SentryWatchdogTerminationScopeObserver to Swift

[noahsmartin]

Pulled out this small swift conversion from my larger dependency container PR to make it easier to review

#skip-changelog

Closes #6470

[codecov]

Codecov Report

❌ Patch coverage is 84.61538% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 87.006%. Comparing base (3319d58) to head (12ba8da).
⚠️ Report is 3 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...ssion/SentryWatchdogTerminationScopeObserver.swift	82.608%	8 Missing ⚠️

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #6469       +/-   ##
=============================================
+ Coverage   86.926%   87.006%   +0.079%     
=============================================
  Files          450       451        +1     
  Lines        37619     37757      +138     
  Branches     17378     17475       +97     
=============================================
+ Hits         32701     32851      +150     
+ Misses        4876      4864       -12     
  Partials        42        42               

Files with missing lines	Coverage Δ
...ors/SentryWatchdogTerminationBreadcrumbProcessor.m	98.648% <100.000%> (+0.077%)	⬆️
Sources/Sentry/SentryDependencyContainer.m	90.170% <100.000%> (-0.084%)	⬇️
...try/SentryWatchdogTerminationTrackingIntegration.m	85.714% <ø> (ø)
...ssion/SentryWatchdogTerminationScopeObserver.swift	82.608% <82.608%> (ø)

... and 25 files with indirect coverage changes

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[itaybre]

LGTM, Just a small question on setContext change

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1219.89 ms	1255.36 ms	35.46 ms
Size	23.74 KiB	1022.38 KiB	998.63 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
7123d8e	1222.27 ms	1262.02 ms	39.76 ms
5258fb8	1207.92 ms	1234.51 ms	26.59 ms
07d7e83	1211.71 ms	1240.08 ms	28.37 ms
be882e4	1199.35 ms	1231.20 ms	31.86 ms
4e3915a	1230.02 ms	1258.90 ms	28.88 ms
7273bf4	1202.42 ms	1227.62 ms	25.21 ms
7bd90de	1233.48 ms	1249.47 ms	15.99 ms
f4f94f5	1216.24 ms	1247.94 ms	31.70 ms
7416ffc	1225.55 ms	1241.80 ms	16.25 ms
d7461dc	1233.69 ms	1255.29 ms	21.60 ms

App size

Revision	Plain	With Sentry	Diff
7123d8e	23.75 KiB	986.80 KiB	963.05 KiB
5258fb8	23.75 KiB	874.45 KiB	850.70 KiB
07d7e83	23.75 KiB	913.27 KiB	889.52 KiB
be882e4	23.75 KiB	946.69 KiB	922.94 KiB
4e3915a	23.75 KiB	858.69 KiB	834.94 KiB
7273bf4	23.75 KiB	908.01 KiB	884.26 KiB
7bd90de	23.75 KiB	933.33 KiB	909.58 KiB
f4f94f5	23.75 KiB	988.02 KiB	964.27 KiB
7416ffc	23.75 KiB	913.63 KiB	889.88 KiB
d7461dc	23.75 KiB	874.45 KiB	850.70 KiB