Improve warning for missing IOable attributes

[unalmis]

No description provided.

[github-actions]

|             benchmark_name             |         dt(%)          |         dt(s)          |        t_new(s)        |        t_old(s)        | 
| -------------------------------------- | ---------------------- | ---------------------- | ---------------------- | ---------------------- |
 test_build_transform_fft_lowres         |     +7.50 +/- 15.20    | +3.77e-02 +/- 7.64e-02 |  5.41e-01 +/- 7.6e-02  |  5.03e-01 +/- 1.1e-02  |
 test_build_transform_fft_midres         |     +1.54 +/- 3.62     | +9.07e-03 +/- 2.13e-02 |  5.98e-01 +/- 2.1e-02  |  5.89e-01 +/- 3.2e-03  |
 test_build_transform_fft_highres        |     +5.22 +/- 3.40     | +5.10e-02 +/- 3.32e-02 |  1.03e+00 +/- 3.2e-02  |  9.76e-01 +/- 7.7e-03  |
 test_equilibrium_init_lowres            |     +1.03 +/- 2.10     | +3.74e-02 +/- 7.59e-02 |  3.66e+00 +/- 7.5e-02  |  3.62e+00 +/- 1.3e-02  |
 test_equilibrium_init_medres            |     +0.01 +/- 0.47     | +2.58e-04 +/- 1.92e-02 |  4.09e+00 +/- 1.5e-02  |  4.09e+00 +/- 1.2e-02  |
 test_equilibrium_init_highres           |     +0.22 +/- 0.96     | +1.18e-02 +/- 5.24e-02 |  5.49e+00 +/- 3.5e-02  |  5.47e+00 +/- 3.9e-02  |
 test_objective_compile_dshape_current   |     +0.10 +/- 1.96     | +3.79e-03 +/- 7.33e-02 |  3.74e+00 +/- 7.0e-02  |  3.74e+00 +/- 2.1e-02  |
 test_objective_compile_atf              |     +0.75 +/- 2.25     | +6.03e-02 +/- 1.81e-01 |  8.14e+00 +/- 6.1e-02  |  8.08e+00 +/- 1.7e-01  |
 test_objective_compute_dshape_current   |     -0.94 +/- 3.54     | -1.18e-05 +/- 4.43e-05 |  1.24e-03 +/- 3.5e-05  |  1.25e-03 +/- 2.7e-05  |
 test_objective_compute_atf              |     -0.54 +/- 6.38     | -2.24e-05 +/- 2.66e-04 |  4.15e-03 +/- 2.1e-04  |  4.18e-03 +/- 1.7e-04  |
 test_objective_jac_dshape_current       |     +1.83 +/- 8.64     | +6.94e-04 +/- 3.27e-03 |  3.86e-02 +/- 2.8e-03  |  3.79e-02 +/- 1.8e-03  |
 test_objective_jac_atf                  |     +2.35 +/- 2.55     | +4.34e-02 +/- 4.72e-02 |  1.89e+00 +/- 3.3e-02  |  1.85e+00 +/- 3.3e-02  |
 test_perturb_1                          |     -0.06 +/- 0.83     | -8.37e-03 +/- 1.07e-01 |  1.29e+01 +/- 9.1e-02  |  1.29e+01 +/- 5.7e-02  |
 test_perturb_2                          |     +0.05 +/- 1.21     | +8.66e-03 +/- 2.16e-01 |  1.79e+01 +/- 1.4e-01  |  1.79e+01 +/- 1.6e-01  |
 test_proximal_jac_atf                   |     -0.46 +/- 0.86     | -3.39e-02 +/- 6.31e-02 |  7.29e+00 +/- 5.4e-02  |  7.33e+00 +/- 3.2e-02  |
 test_proximal_freeb_compute             |     -0.21 +/- 0.88     | -3.74e-04 +/- 1.56e-03 |  1.77e-01 +/- 6.5e-04  |  1.77e-01 +/- 1.4e-03  |
 test_proximal_freeb_jac                 |     +0.13 +/- 1.19     | +9.53e-03 +/- 8.74e-02 |  7.33e+00 +/- 7.0e-02  |  7.32e+00 +/- 5.2e-02  |
 test_solve_fixed_iter                   |     +0.09 +/- 9.94     | +1.35e-02 +/- 1.45e+00 |  1.46e+01 +/- 1.1e+00  |  1.46e+01 +/- 9.8e-01  |

[YigitElma]

@unalmis Since it is a bit late for the USA, I fixed the problem that caused the tests to fail. I believe everything should pass now.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.98%. Comparing base (fd2645a) to head (880e074).
Report is 2120 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1095   +/-   ##
=======================================
  Coverage   94.98%   94.98%           
=======================================
  Files          87       87           
  Lines       21748    21749    +1     
=======================================
+ Hits        20658    20659    +1     
  Misses       1090     1090           

Files with missing lines	Coverage Δ
desc/io/hdf5_io.py	81.96% <100.00%> (+0.09%)	⬆️

[dpanici]

It is not an "input file", it is really an "output file" since it is an .h5, maybe instead say "file being loaded".