fix: Check SessionReplay json's path before reading it

[itaybre]

Fixes a crash when SessionReplay json file does not contain a path field

[github-actions]

	Fails
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## Unreleased

### Fixes

- Check SessionReplay json's path before reading it ([#6538](https://github.com/getsentry/sentry-cocoa/pull/6538))

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Generated by 🚫 dangerJS against e997271

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.910%. Comparing base (707c222) to head (e997271).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #6538       +/-   ##
=============================================
+ Coverage   85.899%   85.910%   +0.010%     
=============================================
  Files          451       451               
  Lines        27482     27482               
  Branches     11970     11968        -2     
=============================================
+ Hits         23607     23610        +3     
+ Misses        3826      3824        -2     
+ Partials        49        48        -1     

Files with missing lines	Coverage Δ
Sources/Sentry/SentrySessionReplayIntegration.m	87.037% <100.000%> (ø)

... and 3 files with indirect coverage changes

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[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1211.60 ms	1249.00 ms	37.40 ms
Size	23.75 KiB	1.00 MiB	1005.04 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
db9572a	1200.27 ms	1234.80 ms	34.53 ms
5258fb8	1207.92 ms	1234.51 ms	26.59 ms
2481950	1221.04 ms	1248.98 ms	27.94 ms
2be5991	1228.55 ms	1264.65 ms	36.10 ms
7d88965	1228.86 ms	1248.53 ms	19.67 ms
ab0ba7e	1216.08 ms	1242.40 ms	26.31 ms
139db8b	1231.50 ms	1258.19 ms	26.69 ms
78af7a9	1225.75 ms	1256.98 ms	31.23 ms
5db87fa	1218.88 ms	1251.53 ms	32.65 ms
b5a7583	1238.22 ms	1263.94 ms	25.71 ms

App size

Revision	Plain	With Sentry	Diff
db9572a	23.75 KiB	858.69 KiB	834.93 KiB
5258fb8	23.75 KiB	874.45 KiB	850.70 KiB
2481950	23.74 KiB	872.74 KiB	849.00 KiB
2be5991	23.75 KiB	994.73 KiB	970.98 KiB
7d88965	23.75 KiB	994.72 KiB	970.98 KiB
ab0ba7e	23.75 KiB	904.54 KiB	880.79 KiB
139db8b	23.75 KiB	920.64 KiB	896.89 KiB
78af7a9	23.75 KiB	990.00 KiB	966.26 KiB
5db87fa	23.75 KiB	926.65 KiB	902.90 KiB
b5a7583	23.75 KiB	913.44 KiB	889.68 KiB