Add `invalid_utf8` to reasons spans could be rejected #9537

Job	Run time
Lint	2m 47s
Benchmark	2m 47s
Build	1m 46s
Run integration tests (test-e2e)	2m 46s
Run integration tests (test-integration-poller)	2m 45s
Check jsonnet & tempo-mixin	54s
Run Unit Tests (test-with-cover-pkg)	2m 47s
Run integration tests (test-e2e-deployments)	2m 48s
Run Unit Tests (test-with-cover-tempodb)	2m 48s
Run integration tests (test-e2e-serverless)	2m 46s
Vendor check	1m 19s
Run Unit Tests (test-with-cover-tempodb-wal)	2m 47s
Run Unit Tests (test-with-cover-others)	2m 46s
Build technical documentation	19s
	32m 5s

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