ci: Skip build (and consecutive steps) when only changing .md files

[mydea]

In order to cut down CI time when releasing, we can skip build & consecutive steps when we notice that only .md files have been changed.

[lforst]

Sorry, not entirely up-to-date with our ci: Will the build step still be executed on release branches?

[mydea]

Sorry, not entirely up-to-date with our ci: Will the build step still be executed on release branches?

On push (for master and release/** branches) we always run all tests!

[Lms24]

Nice! This is a huge win for releasing and time-critical fixes, etc.

[mydea]

FYI I also added a check to skip the codeql-analysis workflow when only .md files have been changed. Now, a PR with only .md changes took me ~30s to complete all workflows!

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	19.72 KB (-0.01% 🔽)
@sentry/browser - ES5 CDN Bundle (minified)	61.13 KB (0%)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	18.51 KB (+0.01% 🔺)
@sentry/browser - ES6 CDN Bundle (minified)	54.66 KB (0%)
@sentry/browser - Webpack (gzipped + minified)	20.28 KB (0%)
@sentry/browser - Webpack (minified)	66.33 KB (0%)
@sentry/react - Webpack (gzipped + minified)	20.3 KB (0%)
@sentry/nextjs Client - Webpack (gzipped + minified)	47.5 KB (0%)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	26.69 KB (+0.02% 🔺)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	25.14 KB (0%)
@sentry/replay ES6 CDN Bundle (gzipped + minified)	41.83 KB (+0.32% 🔺)
@sentry/replay - Webpack (gzipped + minified)	38.08 KB (+0.32% 🔺)