Update MuJoCo internal version to be the external version +1

PiperOrigin-RevId: 623607403
Change-Id: Ia8f6516bb6b2fb6a3ecb8273b59e61667098f308

dist/simulate.rc

@@ -1,8 +1,8 @@
 MUJOCO ICON "mujoco.ico"
 
 1 VERSIONINFO
-FILEVERSION 3,1,4,0
-PRODUCTVERSION 3,1,4,0
+FILEVERSION 3,1,5,0
+PRODUCTVERSION 3,1,5,0
 FILEOS 0x4
 FILETYPE 0x1
 {
@@ -11,9 +11,9 @@ FILETYPE 0x1
     BLOCK "040904b0"
     {
       VALUE "ProductName", "MuJoCo"
-      VALUE "ProductVersion", "3.1.4"
+      VALUE "ProductVersion", "3.1.5"
       VALUE "FileDescription", "MuJoCo"
-      VALUE "FileVersion", "3.1.4"
+      VALUE "FileVersion", "3.1.5"
       VALUE "InternalName", "simulate.exe"
       VALUE "OriginalFilename", "simulate.exe"
       VALUE "CompanyName", "Google DeepMind"