MINOR: [C++][FlightRPC][ODBC] Add Linux validation artifacts for 25.0.1

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Summary

• add a reproducible Ubuntu 24.04 x86_64 build and installation runbook for the Arrow Flight SQL ODBC 25.0.1 driver
• include the stripped shared library, relocatable tar package, and SHA-256 checksums
• add unixODBC install/uninstall helpers with idempotence and registration ownership guards
• add a credential-safe ODBC smoke client and full validation report

Validation

• built from exact commit beccec0d0c451b7aa3e4530416ac431b3c035c69 using the repository-defined Ubuntu 24.04 amd64 configuration
• verified the x86_64 ELF, exported ODBC entry points, and complete dynamic dependency resolution
• verified TLS CA chain and hostname for data.eu.dremio.cloud:443
• completed three authenticated SELECT 1 cycles, including cursor close, statement free, disconnect, and handle cleanup
• verified reproducible packaging, checksums, install, repeat install with UsageCount=1, dynamic load, and uninstall
• ran shellcheck, Bash syntax checks, clang-format, and compiled the smoke client with -Werror

Packaging decision

The 25.0.1 CMake configuration explicitly reports that Linux DEB and RPM installers are not implemented. A forced generic CPack TGZ does not contain the unixODBC registration payload, so this change provides a validated relocatable tar package instead.

Environment limitation

The compiler, userspace, unixODBC manager, driver, and smoke process were all x86_64 Ubuntu 24.04. Execution used Rosetta inside an aarch64 Colima VM, so this validates the x86_64 ABI and end-to-end behavior but is not a native performance result.