SQSCANGHA-135 Fix scanner binaries always re-downloaded due to incompatible 4-part version

GitHub's tool-cache library uses semver.clean() to look up cached tools, which
returns null for 4-part version strings like "8.0.1.6346". This caused
findAllVersions() to filter out any cached directory, resulting in a cache miss
on every run.

The fix converts the 4-part version to a semver pre-release format
(e.g. "8.0.1-build.6346") for tool-cache operations, while keeping the original
version string for download URLs and zip extraction.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

dist/index.js

@@ -3862,6 +3862,19 @@ function getScannerDownloadURL({
 const scannerDirName = (version, flavor) =>
   `sonar-scanner-${version}-${flavor}`;
 
+/**
+ * Converts a 4-part version string (e.g. "8.0.1.6346") to a SemVer 2.0 compatible
+ * string (e.g. "8.0.1-build.6346") for use with GitHub's tool-cache library,
+ * which requires SemVer-compliant version strings.
+ */
+function toSemVer(version) {
+  const parts = version.split(".");
+  if (parts.length === 4) {
+    return `${parts[0]}.${parts[1]}.${parts[2]}-build.${parts[3]}`;
+  }
+  return version;
+}
+
 /*
  * sonarqube-scan-action
  * Copyright (C) 2025 SonarSource SA
@@ -4151,9 +4164,10 @@ async function installSonarScanner({
   skipSignatureVerification = false,
 }) {
   const flavor = getPlatformFlavor(os$1.platform(), os$1.arch());
+  const semVerVersion = toSemVer(scannerVersion);
 
   // Check if tool is already cached
-  let toolDir = find(TOOLNAME, scannerVersion, flavor);
+  let toolDir = find(TOOLNAME, semVerVersion, flavor);
 
   if (!toolDir) {
     info(
@@ -4196,7 +4210,7 @@ async function installSonarScanner({
       scannerDirName(scannerVersion, flavor)
     );
 
-    toolDir = await cacheDir(scannerPath, TOOLNAME, scannerVersion, flavor);
+    toolDir = await cacheDir(scannerPath, TOOLNAME, semVerVersion, flavor);
 
     info(`Sonar Scanner CLI cached to: ${toolDir}`);
   } else {