fix: build.options now have the full path to used platforms (#3042)

Previously the path to the folder containing the platforms was used,
(for exmaple, `/home/cmaglie/.arduino15/packages` instead of
`/home/cmaglie/.arduino15/packages/arduino/hardware/avr/1.8.6`).
This kept the build.options unchanged even if a platform was updated,
leading to a possible cache-reuse even if a full rebuild is required.

Author: cmaglie

commands/service_compile.go

@@ -264,7 +264,6 @@ func (s *arduinoCoreServerImpl) Compile(req *rpc.CompileRequest, stream rpc.Ardu
 		extraCoreBuildCachePaths,
 		int(req.GetJobs()),
 		req.GetBuildProperties(),
-		s.settings.HardwareDirectories(),
 		librariesDirs,
 		s.settings.IDEBuiltinLibrariesDir(),
 		fqbn,

internal/arduino/builder/builder.go

@@ -123,7 +123,6 @@ func NewBuilder(
 	extraCoreBuildCachePaths paths.PathList,
 	jobs int,
 	customBuildProperties []string,
-	hardwareDirs paths.PathList,
 	librariesDirs paths.PathList,
 	builtInLibrariesDirs *paths.Path,
 	fqbn *fqbn.FQBN,
@@ -225,7 +224,7 @@ func NewBuilder(
 		buildPlatform:                 buildPlatform,
 		toolEnv:                       toolEnv,
 		buildOptions: newBuildOptions(
-			hardwareDirs,
+			paths.PathList{targetPlatform.InstallDir, buildPlatform.InstallDir},
 			librariesDirs,
 			builtInLibrariesDirs,
 			buildPath,