aws/install reports "No such file or directory" when `dirname "$@"` contains a space

### Describe the bug

See title.

### Expected Behavior

Silent success.

### Current Behavior

`aws/install: line 78: /tmp/foo: No such file or directory`

Seems to succeed, though.

### Reproduction Steps

```shell
mkdir /tmp/foo\ bar
mv aws /tmp/foo\ bar/
cd /tmp/foo\ bar/
aws/install -i ~/.local/aws-cli -b ~/.local/bin
```

### Possible Solution

Looks like `$INSTALLER_EXE` should be quoted as `"$INSTALLER_EXE` here: https://github.com/aws/aws-cli/blob/b855674c84cfd416a626cbb24edf8d103241b945/exe/assets/install#L78

### Additional Information/Context

_No response_

### CLI version used

aws-cli/2.6.4 Python/3.9.11 Linux/5.15.15-1rodete2-amd64 exe/x86_64.debian prompt/off

### Environment details (OS name and version, etc.)

Linux (Debian) 5.15.15