io/read_metadata: Fix dtype for the index column #3285

Job	Run time
pyright	13s
mypy	1m 2s
test (python=3.9 biopython=1.80)	13m 47s
pathogen-repo-ci (dengue)	2m 46s
test (python=3.9 biopython=1.82)	14m 29s
pathogen-repo-ci (lassa)	7m 50s
check-docs	37s
test (python=3.9 biopython=latest)	13m 38s
pathogen-repo-ci (measles)	1m 21s
pathogen-repo-ci-v0 (avian-flu)	52s
test (python=3.10 biopython=1.80)	15m 33s
pathogen-repo-ci (mpox)	1m 12s
pathogen-repo-ci-v0 (ebola)	1m 4s
test (python=3.10 biopython=1.82)	13m 57s
pathogen-repo-ci (oropouche)	1m 28s
pathogen-repo-ci-v0 (mumps)	55s
test (python=3.10 biopython=latest)	13m 36s
pathogen-repo-ci (rabies)	2m 32s
pathogen-repo-ci-v0 (ncov)	59s
test (python=3.11 biopython=1.80)	14m 28s
pathogen-repo-ci (seasonal-cov)	1m 58s
pathogen-repo-ci-v0 (rsv)	8m 35s
test (python=3.11 biopython=1.82)	13m 25s
pathogen-repo-ci (wnv)	1m 2s
pathogen-repo-ci-v0 (seasonal-flu)	1m 14s
pathogen-repo-ci-v0 (tb)	1m 18s
pathogen-repo-ci (yellow-fever)	4m 30s
test (python=3.11 biopython=latest)	13m 25s
pathogen-repo-ci (zika)	1m 13s
test (python=3.12 biopython=1.82)	21m 11s
test (python=3.12 biopython=latest)	20m 56s
build-docs / build	2m 25s
codecov	12s
release	0s
rebuild-docker-image	0s
	3h 33m 43s

Provide feedback