Fix selection of testing version (#6578)

* mark and skip flaky TestOTelManager_Run

* updated test version selection

* Update testing/upgradetest/versions.go

Co-authored-by: Craig MacKenzie <craig.mackenzie@elastic.co>

* updated versions

* pin 9.0

* pin 9.0

* removed version pin for 9.0

* Update magefile.go

* updated branches

* fix previousMinor for pinned 9.0

---------

Co-authored-by: Craig MacKenzie <craig.mackenzie@elastic.co>
Co-authored-by: Panos Koutsovasilis <panos.koutsovasilis@elastic.co>
(cherry picked from commit 2614cb5)

# Conflicts:
#	testing/integration/testdata/.upgrade-test-agent-versions.yml
#	testing/upgradetest/versions.go

testing/integration/testdata/.upgrade-test-agent-versions.yml

@@ -5,6 +5,12 @@
 # upgrade integration tests.
 
 testVersions:
+<<<<<<< HEAD
+=======
+  - 9.0.0-SNAPSHOT
+  - 8.19.0-SNAPSHOT
+  - 8.17.2
+>>>>>>> 2614cb516 (Fix selection of testing version (#6578))
   - 8.16.4
   - 8.15.5
   - 8.14.3

testing/upgradetest/versions.go

@@ -184,6 +184,7 @@ func findRequiredVersions(sortedParsedVersions []*version.ParsedSemVer, reqs Ver
 	currentMajor := parsedUpgradeToVersion.Major()
 	currentMinor := parsedUpgradeToVersion.Minor()
 
+	skipCurrentMajor := false
 	currentMajorsToFind := reqs.CurrentMajors
 	previousMajorsToFind := reqs.PreviousMajors
 	previousMinorsToFind := reqs.PreviousMinors
@@ -211,15 +212,18 @@ func findRequiredVersions(sortedParsedVersions []*version.ParsedSemVer, reqs Ver
 			currentMajorsToFind-- // counts as the current major as well
 
 		// current majors
-		case currentMajorsToFind > 0 && version.Major() == currentMajor:
+		case currentMajorsToFind > 0 && version.Major() == currentMajor && !skipCurrentMajor:
 			upgradableVersions = append(upgradableVersions, version.String())
 			currentMajorsToFind--
 
 		// previous majors
 		case previousMajorsToFind > 0 && version.Major() < currentMajor:
 			upgradableVersions = append(upgradableVersions, version.String())
 			currentMajor = version.Major()
+			currentMinor = version.Minor()
 			previousMajorsToFind--
+			previousMinorsToFind-- // count as prev minor as well
+			skipCurrentMajor = true
 
 		// since the list is sorted we can stop here
 		default:
@@ -240,6 +244,27 @@ func PreviousMinor() (*version.ParsedSemVer, error) {
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse the current version %s: %w", define.Version(), err)
 	}
+<<<<<<< HEAD
+=======
+
+	// Special case: if we are in the first release of a new major (so vX.0.0), we should
+	// return the latest release from the previous major.
+	if current.Minor() == 0 && current.Patch() == 0 {
+		// Since the current version is the first release of a new major (vX.0.0), there
+		// will be no minor versions in the versions list from the same major (vX). The list
+		// will only contain minors from the previous major (vX-1). Further, since the
+		// version list is sorted in descending order (newer versions first), we can return the
+		// first item from the list as it will be the newest minor of the previous major.
+		for _, v := range versions {
+			if v.Less(*current) {
+				return v, nil
+			}
+		}
+
+		return nil, ErrNoPreviousMinor
+	}
+
+>>>>>>> 2614cb516 (Fix selection of testing version (#6578))
 	for _, v := range versions {
 		if v.Prerelease() != "" || v.BuildMetadata() != "" {
 			continue