refactor: minor code changes in karma `AngularAssetsMiddleware` #1502

Job	Run time
lint	1m 56s
build	10s
e2e_windows (windows-2025, 22, npm, 1)	1m 14s
e2e_windows (windows-2025, 22, npm, 3)	1m 23s
e2e_windows (windows-2025, 22, esbuild, 1)	1m 57s
e2e_windows (windows-2025, 22, npm, 2)	38s
e2e_windows (windows-2025, 22, npm, 5)	1m 15s
e2e_windows (windows-2025, 22, npm, 0)	1m 10s
e2e_windows (windows-2025, 22, esbuild, 3)	1m 12s
e2e_windows (windows-2025, 22, esbuild, 5)	1m 0s
e2e_windows (windows-2025, 22, esbuild, 2)	1m 3s
e2e_windows (windows-2025, 22, npm, 4)	45s
e2e_windows (windows-2025, 22, esbuild, 0)	1m 2s
e2e_windows (windows-2025, 22, esbuild, 4)	1m 0s
e2e-package-managers	0s
publish-snapshots	0s
e2e	0s
e2e-snapshots	0s
test	0s
Browser Compatibility Tests	0s
	15m 45s

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