Remove more side effects from application config testing

[wagoodman]

Follow up to #1640 with a few adjustments:

• remove the symlink during testing since this is writing to paths in the repo (which is not ideal)
• uses the t.Cleanup facility for each test instead of defer calls
• removes a side effect against the xdg package based on XDG_CONFIG_PATH env var that persists after the test in the xdg package
• the homedir package has its own cache which needs to be disabled during testing (since the definition of HOME changes)
• for users that have a config in the home directory we change HOME to always point to a different (bogus) location so that never enters the equation.
• restores the application name from .syft to syft when using the XDG_CONFIG_DIRS path (the original behavior)
• nit: changes t.Fatal to require.NoError calls instead

[github-actions]

Benchmark Test Results

Benchmark results from the latest changes vs base branch

goos: linux
goarch: amd64
pkg: github.com/anchore/syft/test/integration
cpu: Intel(R) Xeon(R) Platinum 8272CL CPU @ 2.60GHz
                                                          │ ./.tmp/benchmark-76bb978.txt │
                                                          │            sec/op            │
ImagePackageCatalogers/alpmdb-cataloger-2                                   11.83m ± 23%
ImagePackageCatalogers/ruby-gemspec-cataloger-2                             866.0µ ±  1%
ImagePackageCatalogers/python-package-cataloger-2                           3.072m ±  2%
ImagePackageCatalogers/php-composer-installed-cataloger-2                   699.7µ ±  1%
ImagePackageCatalogers/javascript-package-cataloger-2                       364.3µ ±  2%
ImagePackageCatalogers/dpkgdb-cataloger-2                                   530.5µ ±  3%
ImagePackageCatalogers/rpm-db-cataloger-2                                   511.5µ ±  2%
ImagePackageCatalogers/java-cataloger-2                                     11.18m ±  1%
ImagePackageCatalogers/graalvm-native-image-cataloger-2                     8.636µ ±  2%
ImagePackageCatalogers/apkdb-cataloger-2                                    573.7µ ±  3%
ImagePackageCatalogers/go-module-binary-cataloger-2                         19.82µ ±  3%
ImagePackageCatalogers/dotnet-deps-cataloger-2                              1.000m ±  2%
ImagePackageCatalogers/portage-cataloger-2                                  332.4µ ±  2%
ImagePackageCatalogers/sbom-cataloger-2                                     107.3µ ±  1%
ImagePackageCatalogers/binary-cataloger-2                                   187.6µ ±  1%
geomean                                                                     478.9µ

                                                          │ ./.tmp/benchmark-76bb978.txt │
                                                          │             B/op             │
ImagePackageCatalogers/alpmdb-cataloger-2                                   5.061Mi ± 0%
ImagePackageCatalogers/ruby-gemspec-cataloger-2                             123.9Ki ± 0%
ImagePackageCatalogers/python-package-cataloger-2                           947.1Ki ± 0%
ImagePackageCatalogers/php-composer-installed-cataloger-2                   155.9Ki ± 0%
ImagePackageCatalogers/javascript-package-cataloger-2                       90.79Ki ± 0%
ImagePackageCatalogers/dpkgdb-cataloger-2                                   144.9Ki ± 0%
ImagePackageCatalogers/rpm-db-cataloger-2                                   170.2Ki ± 0%
ImagePackageCatalogers/java-cataloger-2                                     2.724Mi ± 0%
ImagePackageCatalogers/graalvm-native-image-cataloger-2                     1.555Ki ± 0%
ImagePackageCatalogers/apkdb-cataloger-2                                    129.1Ki ± 0%
ImagePackageCatalogers/go-module-binary-cataloger-2                         3.133Ki ± 0%
ImagePackageCatalogers/dotnet-deps-cataloger-2                              314.8Ki ± 0%
ImagePackageCatalogers/portage-cataloger-2                                  75.43Ki ± 0%
ImagePackageCatalogers/sbom-cataloger-2                                     13.06Ki ± 0%
ImagePackageCatalogers/binary-cataloger-2                                   29.02Ki ± 0%
geomean                                                                     108.4Ki

                                                          │ ./.tmp/benchmark-76bb978.txt │
                                                          │          allocs/op           │
ImagePackageCatalogers/alpmdb-cataloger-2                                    86.71k ± 0%
ImagePackageCatalogers/ruby-gemspec-cataloger-2                              2.049k ± 0%
ImagePackageCatalogers/python-package-cataloger-2                            15.49k ± 0%
ImagePackageCatalogers/php-composer-installed-cataloger-2                    3.458k ± 0%
ImagePackageCatalogers/javascript-package-cataloger-2                        1.214k ± 0%
ImagePackageCatalogers/dpkgdb-cataloger-2                                    2.646k ± 0%
ImagePackageCatalogers/rpm-db-cataloger-2                                    3.759k ± 0%
ImagePackageCatalogers/java-cataloger-2                                      38.27k ± 0%
ImagePackageCatalogers/graalvm-native-image-cataloger-2                       40.00 ± 0%
ImagePackageCatalogers/apkdb-cataloger-2                                     3.437k ± 0%
ImagePackageCatalogers/go-module-binary-cataloger-2                           101.0 ± 0%
ImagePackageCatalogers/dotnet-deps-cataloger-2                               5.011k ± 0%
ImagePackageCatalogers/portage-cataloger-2                                   1.487k ± 0%
ImagePackageCatalogers/sbom-cataloger-2                                       392.0 ± 0%
ImagePackageCatalogers/binary-cataloger-2                                     872.0 ± 0%
geomean                                                                      2.219k