CI: Backport CI/Release related code to v9.3.x (#62752)

* Batch-move everything

* go mod tidy

* make drone

* Remove genversions

* Bump alpine image

* Revert back pkg/build/docker/build.go

* Make sure correct enterprise branch is checked out

* Add enterprise2 version

* Remove extensions

* Bump build container

* backport node 18 test fix

(cherry picked from commit 4ff03fdbfb)

* Update scripts/drone

* Add more commands

* Fix starlark link

* Copy .drone.star

* Add drone target branch for custom events

---------

pkg/build/git/git_test.go

@@ -0,0 +1,56 @@
+package git_test
+
+import (
+	"testing"
+
+	"github.com/grafana/grafana/pkg/build/git"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPRCheckRegexp(t *testing.T) {
+	type match struct {
+		String string
+		Commit string
+		Branch string
+		PR     string
+	}
+
+	var (
+		shouldMatch = []match{
+			{
+				String: "prc-1-a1b2c3d4/branch-name",
+				Branch: "branch-name",
+				Commit: "a1b2c3d4",
+				PR:     "1",
+			},
+			{
+				String: "prc-111-a1b2c3d4/branch/name",
+				Branch: "branch/name",
+				Commit: "a1b2c3d4",
+				PR:     "111",
+			},
+			{
+				String: "prc-102930122-a1b2c3d4/branch-name",
+				Branch: "branch-name",
+				Commit: "a1b2c3d4",
+				PR:     "102930122",
+			},
+		}
+
+		shouldNotMatch = []string{"prc-a/branch", "km/test", "test", "prc", "prc/test", "price"}
+	)
+
+	regex := git.PRCheckRegexp()
+
+	for _, v := range shouldMatch {
+		assert.Truef(t, regex.MatchString(v.String), "regex '%s' should match %s", regex.String(), v)
+		m := regex.FindStringSubmatch(v.String)
+		assert.Equal(t, m[1], v.PR)
+		assert.Equal(t, m[2], v.Commit)
+		assert.Equal(t, m[3], v.Branch)
+	}
+
+	for _, v := range shouldNotMatch {
+		assert.False(t, regex.MatchString(v), "regex '%s' should not match %s", regex.String(), v)
+	}
+}