Apply community-reviewed improvements from Ratis PR #1328 to vulnerability-check workflow

[OneSizeFitsQuorum]

Description

Backports improvements to the weekly CVE scanning workflow that were validated through Apache Ratis PR community review process.

Workflow Simplification

• Removed matrix strategy: Single runner (ubuntu-latest, JDK 17) instead of matrix configuration
• Removed Maven cache: Cache ineffective for weekly scheduled jobs
• Consolidated dependency checks: aggregate step subsumes check step

Enhanced Configuration

• Added conditional execution: Prevents forks from running scheduled scans (github.repository == 'apache/iotdb')
• Added NVD API key support: -DnvdApiKey=${{ secrets.NVD_API_KEY }} parameter for improved CVE data access
• Consistent Maven args: $MAVEN_ARGS variable usage across commands

Improved Clarity

• Renamed DATE_EAST_ASIA → REPORT_DATE: Clearer semantic meaning
• Simplified artifact naming: Removed redundant ${{ runner.os }} component
• Updated step descriptions: More precise naming

Security Hardening

• Added explicit permissions: contents: read follows principle of least privilege

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This PR has:

• been self-reviewed.
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.

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[HTHou]

LGTM