fix: ensure tag name is set when version discovered

When running `release:tag`, the tag name was not getting set once the
version was discovered, which was leading to an error indicating no tag
name was provided.

Author: weierophinney

src/Version/DiscoverVersionEventTrait.php

@@ -15,6 +15,7 @@ trait DiscoverVersionEventTrait
     public function foundVersion(string $version): void
     {
         $this->version = $version;
+        $this->tagName = $this->tagName ?: $version;
     }
 
     public function versionNotAccepted(): void

src/Version/ReleaseEvent.php

@@ -77,12 +77,6 @@ public function setReleaseName(string $releaseName): void
         $this->releaseName = $releaseName;
     }
 
-    public function foundVersion(string $version): void
-    {
-        $this->version = $version;
-        $this->tagName = $this->tagName ?: $version;
-    }
-
     public function releaseCreated(string $release): void
     {
         $this->output()->writeln(sprintf('<info>Created %s<info>', $release));