Fix ArrayInterface minimum version bound

The package uses ArrayInterface.qr_instance (line 268 in src/FastAlmostBandedMatrices.jl),
which was not available in ArrayInterface 7.0-7.4. Testing shows that ArrayInterface 7.5
is the minimum version that provides this function.

Updated the compat entry from "7" to "7.5" to reflect the actual minimum requirement.

Verified by testing with minimum versions - tests pass with ArrayInterface 7.5 but fail
with ArrayInterface 7.0-7.4 due to UndefVarError for qr_instance.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: claude

Project.toml

@@ -15,7 +15,7 @@ PrecompileTools = "aea7be01-6a6a-4083-8856-8a6e6704d82a"
 Reexport = "189a3867-3050-52da-a836-e630ba90ab69"
 
 [compat]
-ArrayInterface = "7"
+ArrayInterface = "7.5"
 ArrayLayouts = "1"
 BandedMatrices = "1"
 ConcreteStructs = "0.2"