Remove old code for folder support in interpreter path setting (#22413)

Closes #12452

src/client/common/configSettings.ts

@@ -2,7 +2,6 @@
 
 // eslint-disable-next-line camelcase
 import * as path from 'path';
-import * as fs from 'fs';
 import {
     ConfigurationChangeEvent,
     ConfigurationTarget,
@@ -35,8 +34,6 @@ import {
 } from './types';
 import { debounceSync } from './utils/decorators';
 import { SystemVariables } from './variables/systemVariables';
-import { getOSType, OSType } from './utils/platform';
-import { isWindows } from './platform/platformService';
 
 const untildify = require('untildify');
 
@@ -390,7 +387,7 @@ export class PythonSettings implements IPythonSettings {
 
     // eslint-disable-next-line class-methods-use-this
     protected getPythonExecutable(pythonPath: string): string {
-        return getPythonExecutable(pythonPath);
+        return untildify(pythonPath);
     }
 
     protected onWorkspaceFoldersChanged(): void {
@@ -489,63 +486,3 @@ function getAbsolutePath(pathToCheck: string, rootDir: string | undefined): stri
     }
     return path.isAbsolute(pathToCheck) ? pathToCheck : path.resolve(rootDir, pathToCheck);
 }
-
-function getPythonExecutable(pythonPath: string): string {
-    pythonPath = untildify(pythonPath) as string;
-
-    // If only 'python'.
-    if (
-        pythonPath === 'python' ||
-        pythonPath.indexOf(path.sep) === -1 ||
-        path.basename(pythonPath) === path.dirname(pythonPath)
-    ) {
-        return pythonPath;
-    }
-
-    if (isValidPythonPath(pythonPath)) {
-        return pythonPath;
-    }
-    // Keep python right on top, for backwards compatibility.
-
-    const KnownPythonExecutables = [
-        'python',
-        'python4',
-        'python3.6',
-        'python3.5',
-        'python3',
-        'python2.7',
-        'python2',
-        'python3.7',
-        'python3.8',
-        'python3.9',
-    ];
-
-    for (let executableName of KnownPythonExecutables) {
-        // Suffix with 'python' for linux and 'osx', and 'python.exe' for 'windows'.
-        if (isWindows()) {
-            executableName = `${executableName}.exe`;
-            if (isValidPythonPath(path.join(pythonPath, executableName))) {
-                return path.join(pythonPath, executableName);
-            }
-            if (isValidPythonPath(path.join(pythonPath, 'Scripts', executableName))) {
-                return path.join(pythonPath, 'Scripts', executableName);
-            }
-        } else {
-            if (isValidPythonPath(path.join(pythonPath, executableName))) {
-                return path.join(pythonPath, executableName);
-            }
-            if (isValidPythonPath(path.join(pythonPath, 'bin', executableName))) {
-                return path.join(pythonPath, 'bin', executableName);
-            }
-        }
-    }
-
-    return pythonPath;
-}
-
-function isValidPythonPath(pythonPath: string): boolean {
-    return (
-        fs.existsSync(pythonPath) &&
-        path.basename(getOSType() === OSType.Windows ? pythonPath.toLowerCase() : pythonPath).startsWith('python')
-    );
-}