chore for release notes table script: fix two matching issues for repo name and PR number

[qiancai]

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• master (the latest development version)
• v7.2 (TiDB 7.2 versions)
• v7.1 (TiDB 7.1 versions)
• v7.0 (TiDB 7.0 versions)
• v6.6 (TiDB 6.6 versions)
• v6.5 (TiDB 6.5 versions)
• v6.1 (TiDB 6.1 versions)
• v5.4 (TiDB 5.4 versions)
• v5.3 (TiDB 5.3 versions)
• v5.2 (TiDB 5.2 versions)
• v5.1 (TiDB 5.1 versions)
• v5.0 (TiDB 5.0 versions)

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• Delete files
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[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: qiancai

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[ran-huang]

/lgtm

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-06-09 05:54:11.985135068 +0000 UTC m=+64066.233056891: ☑️ agreed by ran-huang.