fix: use double brackets for if clause with and & or concatenation

[Gitsarry]

Previous if clause does not work with Bash version 5.2.15(1)-release (x86_64-pc-linux-gnu)
for OS="windows" and RELEASE="11"
(leads to missing tpm="on" line in .conf resulting file)

Fixes #1387

Type of change

[x] Bug fix (non-breaking change which fixes an issue)

Checklist:

• I have performed a self-review of my code
• I have tested my code in common scenarios and confirmed there are no regressions

[Gitsarry]

Better to read and structured code would be:

# Enable TPM for Windows 11 and Windows Server 2022
local -r l_OS_RELEASE="${OS]-${RELEASE}"
if [[ "${l_OS_RELEASE}" == 'windows-11' || "${l_OS_RELEASE}" == 'windows-server-2022' ]]; then