Vendors - Remove invalid Sentry Software entry returning 404

[vitorvasc]

• Removes an invalid entry for the Sentry Software vendor, which is returning an HTTP 404
• Contributes to Refresh refcache #8494

Since this entry has no contact, its URL doesn't exist anymore, and there's no accurate replacement for it, we've discussed the following in #8494:

This entry is a 404,

opentelemetry.io/data/ecosystem/vendors.yaml

Lines 387 to 391 in 45a322d

	- name: Sentry Software
	nativeOTLP: true
	url: https://www.sentrysoftware.com/products/hardware-sentry-opentelemetry-collector.html
	contact:
	oss: false

@svrnm @vitorvasc - I'd say, if an entry has no contact, and it doesn't exist anymore, that we drop it. WDYT? In case we don't want that in this case ... The only two entries I've found on their website are:

• https://www.sentrysoftware.com/integrations/bmc-helix-exporter/
• https://www.sentrysoftware.com/integrations/metricshub/

Originally posted by @chalin in #8494 (comment)

I agree. Looking at web.archive.org, there's an entry from earlier this year showing that this page also had a redirect to an URL that no longer exists, see: https://web.archive.org/web/20250415130819/https://www.sentrysoftware.com/products/hardware-sentry-opentelemetry-collector.html.

Originally posted by @vitorvasc in #8494 (comment)

[svrnm]

@bertysentry can you take a look here