fix(metrics): Ensure string values are interpreted for metrics

[mydea]

Closes #12164

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser	21.77 KB (+0.25% 🔺)
@sentry/browser (incl. Tracing)	32.92 KB (+0.13% 🔺)
@sentry/browser (incl. Tracing, Replay)	68.26 KB (+0.05% 🔺)
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags	61.68 KB (+0.11% 🔺)
@sentry/browser (incl. Tracing, Replay with Canvas)	72.29 KB (+0.04% 🔺)
@sentry/browser (incl. Tracing, Replay, Feedback)	84.35 KB (+0.05% 🔺)
@sentry/browser (incl. Feedback)	37.78 KB (+0.16% 🔺)
@sentry/browser (incl. sendFeedback)	26.34 KB (+0.21% 🔺)
@sentry/browser (incl. FeedbackAsync)	30.76 KB (+0.19% 🔺)
@sentry/react	24.45 KB (+0.17% 🔺)
@sentry/react (incl. Tracing)	35.89 KB (+0.08% 🔺)
@sentry/vue	25.72 KB (+0.25% 🔺)
@sentry/vue (incl. Tracing)	34.74 KB (+0.13% 🔺)
@sentry/svelte	21.91 KB (+0.26% 🔺)
CDN Bundle	24.31 KB (+0.15% 🔺)
CDN Bundle (incl. Tracing)	34.38 KB (+0.14% 🔺)
CDN Bundle (incl. Tracing, Replay)	68.07 KB (+0.08% 🔺)
CDN Bundle (incl. Tracing, Replay, Feedback)	73.06 KB (+0.07% 🔺)
CDN Bundle - uncompressed	71.53 KB (+0.22% 🔺)
CDN Bundle (incl. Tracing) - uncompressed	101.95 KB (+0.16% 🔺)
CDN Bundle (incl. Tracing, Replay) - uncompressed	211.57 KB (+0.08% 🔺)
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed	223.93 KB (+0.08% 🔺)
@sentry/nextjs (client)	35.17 KB (+0.23% 🔺)
@sentry/sveltekit (client)	33.52 KB (+0.21% 🔺)
@sentry/node	114.1 KB (+0.01% 🔺)
@sentry/aws-serverless	103 KB (+0.01% 🔺)