Reuse installed target dir providers in init

In init, we can check to see if the target dir already has the
provider we are seeking and skip further querying/installing of
that provider.

internal/providercache/installer.go

@@ -310,6 +310,20 @@ NeedProvider:
 			preferredHashes = lock.PreferredHashes()
 		}
 
+		// If our target directory already has the provider version that fulfills the lock file, carry on
+		if installed := i.targetDir.ProviderVersion(provider, version); installed != nil {
+			if len(preferredHashes) > 0 {
+				if matches, err := installed.MatchesAnyHash(preferredHashes); err != nil {
+					return nil, fmt.Errorf(
+						"failed to calculate checksum for installed copy of %s %s in %s: %s",
+						installed.Provider, installed.Version, i.targetDir.baseDir, err,
+					)
+				} else if matches {
+					continue
+				}
+			}
+		}
+
 		if i.globalCacheDir != nil {
 			// Step 3a: If our global cache already has this version available then
 			// we'll just link it in.