refactor(pwsh): only install PSFzf if not found

dots/.config/powershell/Microsoft.PowerShell_profile.ps1

@@ -1,3 +1,7 @@
-Install-Module -Name PSFzf -RequiredVersion 2.5.10
+if (-Not (Get-Module -ListAvailable -Name PSFzf))
+{
+    Install-Module -Name PSFzf
+}
+
 Set-PsFzfOption -PSReadlineChordProvider 'Ctrl+t' -PSReadlineChordReverseHistory 'Ctrl+r'
 Set-PSReadLineKeyHandler -Key Tab -ScriptBlock { Invoke-FzfTabCompletion }