Fix registry resolution of major alternate package manifests (#8188)

### Motivation:

Let's take the following `Package.swift`:
```swift
// swift-tools-version: 5.7

import PackageDescription

let package = Package(
    name: "Library",
    dependencies: [
        .package(id: "AliSoftware.OHHTTPStubs", exact: "9.0.0")
    ]
)
```

You can find the `OHHTTPStubs` dependency at that version
[here](https://github.com/AliSoftware/OHHTTPStubs/tree/e92b5a5746ef16add2a1424f1fc19529d9a75cde).

The dependency has two manifests:
- `Package.swift` with `swift-tools-version` at `4.0`
- `[email protected]` with `swift-tools-version` at `5.0`

When resolving packages via the registry, SwiftPM should use the
`[email protected]`. However, instead SwiftPM fails with:
```
Running resolver because the following dependencies were added: 'AliSoftware.OHHTTPStubs' (AliSoftware.OHHTTPStubs)
Computing version for AliSoftware.OHHTTPStubs
info: 'AliSoftware.OHHTTPStubs': retrieving AliSoftware.OHHTTPStubs metadata from http://localhost:8080/api/accounts/tuist/registry/swift/AliSoftware/OHHTTPStubs
info: 'AliSoftware.OHHTTPStubs': retrieving AliSoftware.OHHTTPStubs 9.0.0 metadata from http://localhost:8080/api/accounts/tuist/registry/swift/AliSoftware/OHHTTPStubs/9.0.0
info: 'AliSoftware.OHHTTPStubs': retrieving available manifests for AliSoftware.OHHTTPStubs 9.0.0 from http://localhost:8080/api/accounts/tuist/registry/swift/AliSoftware/OHHTTPStubs/9.0.0/Package.swift
info: 'AliSoftware.OHHTTPStubs': retrieving AliSoftware.OHHTTPStubs 9.0.0 metadata from http://localhost:8080/api/accounts/tuist/registry/swift/AliSoftware/OHHTTPStubs/9.0.0
info: 'AliSoftware.OHHTTPStubs': retrieving AliSoftware.OHHTTPStubs 9.0.0 manifest from http://localhost:8080/api/accounts/tuist/registry/swift/AliSoftware/OHHTTPStubs/9.0.0/Package.swift?swift-version=5.0.0
error: failed locating placeholder manifest for 5.0.0
```

### Modifications:

The reason for the error is because when looking up the alternate
package manifests from the downloaded source archive, SwiftPM doesn't
try to find `[email protected]` – only `[email protected]` and
`[email protected]`.

When both minor and patch versions of the swift tools version are 0,
SwiftPM should try to use the `[email protected]` alternate
manifest.

### Result:

`swift package resolve` will work for packages in a registry that have
alternate manifests in the format of `[email protected]`.

Author: fortmarek

Sources/Workspace/PackageContainer/RegistryPackageContainer.swift

@@ -200,6 +200,8 @@ public class RegistryPackageContainer: PackageContainer {
                                             return true
                                         } else if preferredToolsVersion.patch == 0, file == Manifest.basename + "@swift-\(preferredToolsVersion.major).\(preferredToolsVersion.minor).swift" {
                                             return true
+                                        } else if preferredToolsVersion.patch == 0, preferredToolsVersion.minor == 0, file == Manifest.basename + "@swift-\(preferredToolsVersion.major).swift" {
+                                            return true
                                         } else {
                                             return false
                                         }

Tests/WorkspaceTests/RegistryPackageContainerTests.swift

@@ -226,7 +226,7 @@ final class RegistryPackageContainerTests: XCTestCase {
         let v5_3_3 = ToolsVersion(string: "5.3.3")!
 
         func createProvider(_ toolsVersion: ToolsVersion) throws -> PackageContainerProvider {
-            let supportedVersions = Set<ToolsVersion>([ToolsVersion.v5_3, v5_3_3, .v5_4, .v5_5])
+            let supportedVersions = Set<ToolsVersion>([ToolsVersion.v5, .v5_3, v5_3_3, .v5_4, .v5_5])
             let registryClient = try makeRegistryClient(
                 packageIdentity: packageIdentity,
                 packageVersion: packageVersion,
@@ -334,6 +334,14 @@ final class RegistryPackageContainerTests: XCTestCase {
             let manifest = try await container.loadManifest(version: packageVersion)
             XCTAssertEqual(manifest.toolsVersion, .v5_5)
         }
+        
+        do {
+            let provider = try createProvider(.v5) // the version of the alternate
+            let ref = PackageReference.registry(identity: packageIdentity)
+            let container = try await provider.getContainer(for: ref) as! RegistryPackageContainer
+            let manifest = try await container.loadManifest(version: packageVersion)
+            XCTAssertEqual(manifest.toolsVersion, .v5)
+        }
     }
 
     func makeRegistryClient(
@@ -492,7 +500,13 @@ final class RegistryPackageContainerTests: XCTestCase {
         guard let registryIdentity = identity.registry else {
             preconditionFailure("invalid registry identity: '\(identity)'")
         }
-        let versionString = version.patch == 0 ? "\(version.major).\(version.minor)" : version.description
+        let versionString = if version.patch == 0 && version.minor == 0 {
+            "\(version.major)"
+        } else if version.patch == 0 {
+            "\(version.major).\(version.minor)"
+        } else {
+            version.description
+        }
         return "<http://localhost/\(registryIdentity.scope)/\(registryIdentity.name)/\(version)/\(Manifest.filename)?swift-version=\(version)>; rel=\"alternate\"; filename=\"\(Manifest.basename)@swift-\(versionString).swift\"; swift-tools-version=\"\(version)\""
     }
 }