Current version includes vulnerable packages

[lengau]

I'm not sure whether either of these are actually exploitable here, but since I'm updating the version number to 1.2 anyway for bot configuration I figured I might as well report & fix.

Audit result

$ npm audit
# npm audit report

@actions/core  <=1.9.0
Severity: moderate
@actions/core has Delimiter Injection Vulnerability in exportVariable - https://github.com/advisories/GHSA-7r3h-m5j6-3q42
fix available via `npm audit fix`
node_modules/@actions/core

node-fetch  <2.6.7
Severity: high
node-fetch is vulnerable to Exposure of Sensitive Information to an Unauthorized Actor - https://github.com/advisories/GHSA-r683-j2x4-v87g
fix available via `npm audit fix`
node_modules/node-fetch

2 vulnerabilities (1 moderate, 1 high)

To address all issues, run:
  npm audit fix