weights: add release branches for cosmos-sdk, jellyfin, grafana, neovim, and metamask-extension

[aviu16]

Summary

Add active release branches as additional_acceptable_branches for five whitelisted repos so merged contributions targeting LTS / patch releases are recognized in miner accounting.

Consolidated per @anderdc's note on #787 ("No reason for separation").

Why

Each of these repos cuts release branches that receive substantial merged-PR traffic. Without these overrides, valid merges to release/* are not currently scoreable since only the default branch is recognized.

cosmos/cosmos-sdk (last 100 merged):

• 41 merges into release/v0.54.x, most recent #26336 on 2026-04-23
• 4 merges into release/v0.53.x, most recent #26308 on 2026-04-15

jellyfin/jellyfin (last 100 merged):

• 16 merges into release-10.11.z, most recent #16540 on 2026-04-03

grafana/grafana (last 100 merged):

• 15 merges into release-13.0.2, most recent #123558 on 2026-04-24

neovim/neovim (last 100 merged):

• 46 merges into release-0.12, most recent #39377 on 2026-04-24

MetaMask/metamask-extension (last 100 merged):

• 17 merges into release/13.28.0, most recent #42097 on 2026-04-23
• 6 merges into release/13.29.0, most recent #42124 on 2026-04-24

Change

"cosmos/cosmos-sdk": {
  "additional_acceptable_branches": [
    "release/v0.54.x",
    "release/v0.53.x"
  ],
  "weight": 0.0916
},
"grafana/grafana": {
  "additional_acceptable_branches": [
    "release-13.0.2"
  ],
  "weight": 0.1136
},
"jellyfin/jellyfin": {
  "additional_acceptable_branches": [
    "release-10.11.z"
  ],
  "weight": 0.0607
},
"MetaMask/metamask-extension": {
  "additional_acceptable_branches": [
    "release/13.28.0",
    "release/13.29.0"
  ],
  "weight": 0.0806
},
"neovim/neovim": {
  "additional_acceptable_branches": [
    "release-0.12"
  ],
  "weight": 0.0785
}

[aviu16]

Folded in #787 / #788 / #789 per your note. Now covers cosmos-sdk, jellyfin, grafana, neovim, and metamask-extension in one PR. Diff is +17 lines, single file.