vorbis: fix MinGW shared + modernize more for conan v2

[SpaceIm]

• When you build shared vorbis/1.3.7 with MinGW GCC, you get these errors: Add library name to def files xiph/vorbis#74 (comment).
  .def files are patched with win32/*.def: remove LIBRARY directives xiph/vorbis#76 in order to fix this issue
• modernize:
  • add package_type
  • use export_conandata_patches
  • use rm_safe
  • remove CMAKE_POLICY_DEFAULT_CMP0077 workaround (not needed after conan 1.54.0)

---

• I've read the contributing guidelines.
• I've used a recent Conan client version close to the currently deployed.
• I've tried at least one configuration locally with the conan-center hook activated.

[conan-center-bot]

Conan v1 pipeline ✔️

All green in build 2 (2a264ce4e13045efe776db979610cd1f1b859ed6):

• vorbis/1.3.7:
  All packages built successfully! (All logs)

• vorbis/1.3.6:
  All packages built successfully! (All logs)

---

Conan v2 pipeline ✔️

Note: Conan v2 builds are now mandatory. Please read our discussion about it.

All green in build 2 (2a264ce4e13045efe776db979610cd1f1b859ed6):

• vorbis/1.3.7:
  All packages built successfully! (All logs)

• vorbis/1.3.6:
  All packages built successfully! (All logs)

[uilianries]

LGTM