chore: remove panic from uverse (gnolang#2626)

This function in uverse is misleading, because it's never actually
called. Panics are converted to a `*PanicStmt`, not as function calls.

<details><summary>Contributors' checklist...</summary>

- [x] Added new tests, or not needed, or not feasible
- [x] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [x] Updated the official documentation or not needed
- [x] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [x] Added references to related issues and PRs
- [x] Provided any useful hints for running manual tests
- [x] Added new benchmarks to [generated
graphs](https://gnoland.github.io/benchmarks), if any. More info
[here](https://github.com/gnolang/gno/blob/master/.benchmarks/README.md).
</details>

gnovm/pkg/gnolang/misc.go

@@ -150,6 +150,10 @@ func isReservedName(n Name) bool {
 
 // scans uverse static node for blocknames. (slow)
 func isUverseName(n Name) bool {
+	if n == "panic" {
+		// panic is not in uverse, as it is parsed as its own statement (PanicStmt)
+		return true
+	}
 	uverseNames := UverseNode().GetBlockNames()
 	for _, name := range uverseNames {
 		if name == n {

gnovm/pkg/gnolang/uverse.go

@@ -928,17 +928,7 @@ func UverseNode() *PackageNode {
 			return
 		},
 	)
-	defNative("panic",
-		Flds( // params
-			"err", AnyT(), // args[0]
-		),
-		nil, // results
-		func(m *Machine) {
-			arg0 := m.LastBlock().GetParams1()
-			xv := arg0.Deref()
-			panic(xv.Sprint(m))
-		},
-	)
+	// NOTE: panic is its own statement type, and is not defined as a function.
 	defNative("print",
 		Flds( // params
 			"xs", Vrd(AnyT()), // args[0]