Update dependency @webcomponents/custom-elements to v1.6.0

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
@webcomponents/custom-elements (source)	1.1.0 -> 1.6.0

---

Release Notes

webcomponents/polyfills (@​webcomponents/custom-elements)

v1.6.0

Compare Source

• Add support for Element.toggleAttribute() (#​541)
• Update dependencies (#​542)

v1.5.1

Compare Source

• Don't write to window.CustomElementsRegistry unless we're also writing to window.customElements. (#​524)
• Update TypeScript and upstream internal changes.
  (#​525)

v1.5.0

Compare Source

• Add TS externs. (#​457)

v1.4.3

Compare Source

• Maintenance release (no user-facing changes)

v1.4.2

Compare Source

• Type annotation improvements for Closure (#​287)
• README improvements (#​169)

v1.4.1

Compare Source

• Fix bug that prevented elements in the main document from being upgraded
  (#​283)

v1.4.0

Compare Source

• Convert to TypeScript
  (#​246)

v1.3.2

Compare Source

• Maintenance release (no user-facing changes)

v1.3.1

Compare Source

• Remove warnings about insertAdjacentElement and insertAdjacentHTML not
  being patched (#​229)
• Fix incorrect polyfillWrapFlushCallback example in README
  (#​219)

v1.2.1

Compare Source

v1.2.0

Compare Source

v1.1.3

Compare Source

v1.1.2

Compare Source

v1.1.1

Compare Source

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR has been generated by Mend Renovate. View repository job log here.