ci: Remove unused strategy sections from non-matrix jobs (#566)

## Summary

Removes unnecessary `strategy` sections from jobs that don't use a
matrix.

## Changes

- Removed `strategy: fail-fast: false` from `ubuntu`, `macos`, `windows`
jobs in `test.yml`
- Removed `strategy: fail-fast: false` from `sanitizer-test` job in
`sanitizer_test.yml`

## Rationale

The `fail-fast` option only applies to matrix jobs where multiple
configurations run in parallel. For single jobs without a matrix, this
setting has no effect and generates schema warnings.

Jobs with matrices (like `meson` and `verify`) retain their strategy
configuration.

Author: kevinjqliu

.github/workflows/sanitizer_test.yml

@@ -37,8 +37,6 @@ jobs:
   sanitizer-test:
     name: "ASAN and UBSAN Tests"
     runs-on: ubuntu-24.04
-    strategy:
-      fail-fast: false
     steps:
       - name: Checkout iceberg-cpp
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2

.github/workflows/test.yml

@@ -41,8 +41,6 @@ jobs:
     name: AMD64 Ubuntu 24.04
     runs-on: ubuntu-24.04
     timeout-minutes: 30
-    strategy:
-      fail-fast: false
     steps:
       - name: Checkout iceberg-cpp
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
@@ -65,8 +63,6 @@ jobs:
     name: AArch64 macOS 26
     runs-on: macos-26
     timeout-minutes: 30
-    strategy:
-      fail-fast: false
     steps:
       - name: Checkout iceberg-cpp
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
@@ -80,8 +76,6 @@ jobs:
     name: AMD64 Windows 2025
     runs-on: windows-2025
     timeout-minutes: 60
-    strategy:
-      fail-fast: false
     steps:
       - name: Checkout iceberg-cpp
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2