test: Add missing test for transaction name

[philipphofmann]

The serialization of transactionContext.name was missing a test case.

#skip-changelog

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1228.94 ms	1245.64 ms	16.70 ms
Size	20.76 KiB	432.42 KiB	411.66 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
56ec5d0	1194.39 ms	1236.94 ms	42.55 ms
302ee8b	1194.02 ms	1223.34 ms	29.32 ms
1bd0055	1207.57 ms	1223.10 ms	15.53 ms
8f397a7	1252.37 ms	1274.80 ms	22.43 ms
33b2f51	1251.24 ms	1259.18 ms	7.94 ms
d40512b	1231.12 ms	1244.54 ms	13.42 ms
dc0db9e	1246.06 ms	1260.46 ms	14.40 ms
c319795	1205.12 ms	1231.20 ms	26.08 ms
b2f82fa	1236.94 ms	1262.86 ms	25.92 ms
c9724f9	1199.38 ms	1229.54 ms	30.16 ms

App size

Revision	Plain	With Sentry	Diff
56ec5d0	20.76 KiB	414.44 KiB	393.68 KiB
302ee8b	20.76 KiB	419.62 KiB	398.87 KiB
1bd0055	20.76 KiB	420.22 KiB	399.46 KiB
8f397a7	20.76 KiB	420.55 KiB	399.79 KiB
33b2f51	20.76 KiB	432.17 KiB	411.41 KiB
d40512b	20.76 KiB	427.77 KiB	407.00 KiB
dc0db9e	20.76 KiB	419.62 KiB	398.86 KiB
c319795	20.76 KiB	431.99 KiB	411.22 KiB
b2f82fa	20.76 KiB	419.62 KiB	398.86 KiB
c9724f9	20.76 KiB	427.66 KiB	406.90 KiB