ci: Fix size check action to run on master

[mydea]

As pointed out by @AbhiPrasad, the size check action on CI has not been properly running since we merged #6180.

After some investigation, I think I've pinned the culprit down:

Basically, in that PR I "fixed" an if condition for the size limit action job. Previously, because the condition had a wrong syntax, it was always running.

if: ${{ github.event_name == 'pull_request' }} || ${{ startsWith(github.ref, 'refs/heads/master/') }}

This was incorrect because either we need to wrap the whole expression with ${{ }}, or none of it (as if auto-wraps it). With the original statement, it always evaluated to a truthy expression.

So I "fixed" the syntax, however didn't notice that one part of the check was incorrect:

if: github.event_name == 'pull_request' || startsWith(github.ref, 'refs/heads/master/')

Actually, refs/heads/master/ never matches - the trailing / is incorrect, I believe - should be:

if: github.event_name == 'pull_request' || github.ref == 'refs/heads/master'

So this PR actually fixes that statement with the proper branch name (hopefully). Also, as far as I can tell from github docs, we don't actually need the startsWith stuff here.

[AbhiPrasad]

Thanks for taking a look!

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	19.52 KB (added)
@sentry/browser - ES5 CDN Bundle (minified)	60.37 KB (added)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	18.17 KB (added)
@sentry/browser - ES6 CDN Bundle (minified)	53.72 KB (added)
@sentry/browser - Webpack (gzipped + minified)	19.91 KB (added)
@sentry/browser - Webpack (minified)	65.18 KB (added)
@sentry/react - Webpack (gzipped + minified)	19.94 KB (added)
@sentry/nextjs Client - Webpack (gzipped + minified)	45.93 KB (added)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	26.36 KB (added)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	24.77 KB (added)