cleanup [python]: Use fake ctor instead of static Instance field for VirtualEnvReader.

Use `VirtualEnvReader()` instead of `VirtualEnvReader.Instance` as it is shorter and more idiomatic

Space-RevId: 58448643037948f1e7dc2e84303844b50bd56ee9

GitOrigin-RevId: 35d5b67b8a2d2964ec4b5f611b0f081ac722be2a

python/openapi/src/com/jetbrains/python/venvReader/VirtualEnvReader.kt

@@ -45,7 +45,6 @@ class VirtualEnvReader private constructor(
     null -> null
   })
 
-  private constructor() : this(forcedVars = null, forcedOs = null)
 
   /**
    * Dir with virtual envs
@@ -222,8 +221,7 @@ class VirtualEnvReader private constructor(
 
 
   companion object {
-    @JvmStatic
-    val Instance: VirtualEnvReader = VirtualEnvReader()
+    internal val Instance: VirtualEnvReader = VirtualEnvReader(forcedVars = null, forcedOs = null)
 
 
     /**
@@ -241,4 +239,10 @@ class VirtualEnvReader private constructor(
     private val WIN_BINS = setOf("pypy.exe", "python.exe")
     private fun getLocalEelIfApp(): EelApi? = if (ApplicationManager.getApplication() != null) localEel else null
   }
-}
+}
+
+/**
+ * Default (production) instance
+ */
+@ApiStatus.Internal
+fun VirtualEnvReader(): VirtualEnvReader = Instance