chore: remove stray space from UV_PYTHON_INSTALL_DIR message (#720)

I was mildly annoyed seeing

```
Post job cleanup.
UV_CACHE_DIR is already set to /home/runner/work/_temp/setup-uv-cache
UV_PYTHON_INSTALL_DIR is already set to  /home/runner/work/_temp/uv-python-dir
```
in my GHA log. 😄 

This fixes that to
```
Post job cleanup.
UV_CACHE_DIR is already set to /home/runner/work/_temp/setup-uv-cache
UV_PYTHON_INSTALL_DIR is already set to /home/runner/work/_temp/uv-python-dir
```
as is good and proper.

Author: akx

dist/save-cache/index.js

@@ -155,7 +155,7 @@ function getCacheDirFromConfig(): string | undefined {
 export function getUvPythonDir(): string {
   if (process.env.UV_PYTHON_INSTALL_DIR !== undefined) {
     core.info(
-      `UV_PYTHON_INSTALL_DIR is already set to  ${process.env.UV_PYTHON_INSTALL_DIR}`,
+      `UV_PYTHON_INSTALL_DIR is already set to ${process.env.UV_PYTHON_INSTALL_DIR}`,
     );
     return process.env.UV_PYTHON_INSTALL_DIR;
   }