ci: adds Go 1.19.0-rc.2 into matrix (#714)

This adds the 1.19.0-rc2. in the testing matrix.

This also formats the Godocs across the codebase, as
Go 1.19 has started auto-formatting Godoc. https://github.com/tetratelabs/wazero/issues/426

Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>

internal/wazeroir/compiler.go

@@ -159,7 +159,7 @@ type compiler struct {
 }
 
 // For debugging only.
-//nolint
+// nolint
 func (c *compiler) stackDump() string {
 	strs := make([]string, 0, len(c.stack))
 	for _, s := range c.stack {