fix: dateTime usage only available in go1.20 (#2982)

instead use a simpler normalizer for timestamp
to be user friendly without spaces.

For example

```
selected_files_20091110T230000Z.zip
```

.github/workflows/cross-compile.yaml

@@ -26,7 +26,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        go-version: [ 1.20.x ]
+        go-version: [ 1.19.x, 1.20.x ]
         os: [ ubuntu-latest ]
     steps:
       - name: Check out code