tests: remove unnecessary Cwd imports

Dependencies

• [2] 3AKZKWCR RunCommand: Test
• [3] F7WJVMRV tests/input-types: split out scminputs into individual tests
• [4] 3G475GRT Split out dependent tests in to its own .t
• [5] YIZWKGFI tests: add jobsdir and testdir to ctx hash
• [6] HX4QYOYA add first evaluations tests
• [7] 5SMQ2PLK Fix tests
• [8] UIA3ULNU Give each test its own Nix directories
• [9] 4QI6G7YB tests: replace the flat list of contexts with a hash
• [10] VU2OLHD2 Move most of AddBuilds to hydra-eval-jobset

Change contents

• edit in tests/build-products.t at line 2
  [4.924]→[4.924:933](∅→∅)
  − use Cwd;
• edit in tests/evaluate-basic.t at line 3
  [4.45]→[4.45:54](∅→∅)
  − use Cwd;
• edit in tests/evaluate-dependent-jobsets.t at line 2
  [4.14]→[4.14:23](∅→∅)
  − use Cwd;
• edit in tests/input-types/bzr-checkout.t at line 2
  [3.52]→[3.52:61](∅→∅)
  − use Cwd;
• edit in tests/input-types/bzr.t at line 2
  [3.601]→[3.601:610](∅→∅)
  − use Cwd;
• edit in tests/input-types/darcs.t at line 2
  [3.1101]→[3.1101:1110](∅→∅)
  − use Cwd;
• edit in tests/input-types/deepgit.t at line 2
  [3.1613]→[3.1613:1622](∅→∅)
  − use Cwd;
• edit in tests/input-types/git-rev.t at line 2
  [3.2157]→[3.2157:2166](∅→∅)
  − use Cwd;
• edit in tests/input-types/git.t at line 2
  [3.2735]→[3.2735:2744](∅→∅)
  − use Cwd;
• edit in tests/input-types/hg.t at line 2
  [3.3235]→[3.3235:3244](∅→∅)
  − use Cwd;
• edit in tests/input-types/svn-checkout.t at line 2
  [3.3729]→[3.3729:3738](∅→∅)
  − use Cwd;
• edit in tests/input-types/svn.t at line 2
  [3.4278]→[3.4278:4287](∅→∅)
  − use Cwd;
• edit in tests/plugins/runcommand.t at line 4
  [2.1288]→[2.1288:1297](∅→∅)
  − use Cwd;